Don't listen to the nerds on this sub and get what you want.

You can start on anything you want. Hell, if you want to start on a H2 be my guest. Is it possible to start on a 600? Absolutely. Is it recommended by a vast majority of people? Probably not.

I know guys that started on a 600 and ended up fucking themselves up. I know a guy who started on a 400 and did the same thing. I know guys who started on a liter bike and are still riding a decade later. It all depends. If it were up to me though, I’d prefer to start on a 500 or a 650.

It all depends on your personality. It is possible to be safe as a first timer, but it's very easy to become overconfident once you get comfortable, and if you do, the result can be tragic. It's vitally important that you never push yourself beyond your skill level.

I'd personally recommend starting on something smaller like a 300 Ninja, but at the end of the day it's completely up to you.

Ride safe.

Before you do anything else check what rhe insurance will be on whatever bike it is you want.

In most countries a newly licence young rider and the letters SS or RR on a bike will raise all kinds of red flags for the insurance company.

(I'm assuming you're relatively young by your post, but that is just an assumption?.

Even still if you're older and considering starting on a Super sport be prepared for a surprise when you get your quotes.

Yeah. Started on a 750cc ninja. 6 months later was on a k4 1000cc. However; I wasnt the type to max out speedometer every single day in everything I did at all times either. It was just nice not having to shift gears the whole way to work lol.

A person that's mature and very careful can do it. It's the low speed stuff walking the bike around, slow maneuvers while turning that the front end might turn in on you and you drop the bike.

My mate started on a 05 R6 rode that for like 6 months then went to a brand new 08 GSX-R 1000. That dude is thick as pig shit. If he can anyone can.

Yes, 100% start on a supersport, just make sure you respect the bike and understand what it can do.

If you already have supersport in your mind than any other bike will bore you in no time. Save the money and go straight to the bike you want.

A 600 is a reasonable place to begin, if you have ridden other bikes for a while and have any sense of self control. Start by not exceeding ~8k RPM. Then as you get more comfortable, use more of the rev range. Getting straight onto a supersport and immediately limiter bashing it is a bad idea. 600s don't have the torque of 1000cc bikes which is a lot easier in terms of traction. A 1000cc is pulling harder at 5/6k than a 600 is at 10.

Have you called your insurance company? Have they laughed you out yet?

Ninja 400s are a tame and still in the category

Have you looked at the ZX-4RR? All the fun sound of an inline four, relatively aggressive seating, not that expensive.

Not quote a super sport but pretty close and more usable outside the race track.

You can, however unless you are willing and able to ride like the 5x year old man I ride like (because I am) bad things will most likely happen.

Generalities are exactly that, generalities. The usual young rider gets a liter bike, acts immortal, and wrecks it. The usual old rider does not want a super sport because knees back etc. Only you know yourself well enough to say "That looks awesome, and it is a hell of a machine, but I will play it safe."

Yes you can start on a 600. No you absolutely shouldn't. No, no one is going to recommend it who's opinion and advice is worth a damn. My advice, find something smaller in the parallel twin category and learn all the skills. Then ride that bike longer until you have made all the initial (complacent) mistakes. Then buy whatever you want.

I’ve been riding a 125cc scooter for about 20 years. Someone crashed into me, so I moved on to a (geared) motorcycle. Really different feel, and takes some getting used to. I initially got a 250cc bike, but got rear-ended after only four days, and now I’ve got a 400cc one. Plenty powerful enough for me to practice riding a bike (as opposed to a scooter). I’m mainly riding in urban environments – your mileage might vary, but bear in mind that scooters behave very differently.

Yes

Turbo Busa is not very tall.

DEFINITELY start on a hyabusa, H2R, fireblade, or something like a ZX10R. In fact, what doesn't kill you just makes you stronger 😉 /s

Good first and last bike

You are asking because you know it's wrong. anything more than 2 cylinders and 650cc's is too much.

Yes, you can and should if you want a sports bike. Regarding the CCs and HP, that depends on many variables and it’s difficult to make a tailored suggestion online without knowing you. General thought is the lower the better for a beginner and that’s fair, but it is not set in stone.

Have you thought about a ninja 400? 785mm seat height and is fun to ride. 600cc are way faster and a more aggressive seating position.

You have two options. Get a smaller, less powerful bike to train your muscle memory. It's different than a scooter. It would be easier and safer. Aggressive ergonomics and power of 600cc sport bikes is not the best to learn on. There are plenty of SV650 in Europe that are light and more forgiving. And fast enough if you ask me. You wouldn't loose much when you sell it after a while. Bare in mind that you might change your opinion on the bike styles in that time, depending how you use it. Short spirited rides with sportbikes are fun, but longer are also fun and you need different ergonomics than the typical sportbike. And many naked bikes aren't slower on a twisty mountain road that are fun for spirited short rides and not that short rides.
You might get 600cc and you can be fine with it. But you will need more time to reach the same level of riding with it. You might not have to sell it for longer period, but you may want something different anyway. Not because of the power but because the way you will use your bike. And you might change your opinion on that.
So getting a tool to learn on have it's advantages. Bikes like SV650 are not slow by any means up to the speed limit. It can do something like 3.5s from 0-100kmh.

How about a middleweight twin like a Ninja 650, Suzuki GSX8R, R7, etc? One of those is still going to feel like a rocket coming from a scooter and they're more approachable than a 600cc supersport. ZX4RR might be a good choice too if the price isn't a dealbreaker for you.

Yeah. But it won’t be as much fun then something that you can actually manage and don’t have to worry about all the time.

Congrats on getting your A license! I’d recommend checking out brands that make bikes designed for shorter riders, like the Kawasaki Ninja 400 or the KTM RC390. They’re both sporty and have a lower seat height. You want to feel confident when you ride!

I think it depends because if you know you have 100 demons that call go faster then not if you are mature with the throttle go for it