Switching from 250cc to 600cc inline 4?

[Spooklorky]

Hi, Im looking to buy my first motorcycle but I've got a few questions to help narrow down what bike I should get. I plan to just ride for fun, I have a car to commute and I've always wanted a fast sports bike so my goal is to get enough experience riding on a beginner bike within a couple years to be able to buy a 600 cc inline 4 and not crash it instantly. I plan on taking a msf course this spring before I ride anything.

I have been eyeballing the amazon clone of the venom x22 efi superbike because its a cheap and convenient option that people seem satisfied with as a beginner bike. I have also been eyeballing the ninja 400 because it seems to be a very well rounded beginner sportsbike.

I know the venom x22 superbike makes like 17ish horsepower and the Kawasaki ninja 400 makes like 48 horsepower and they are both considered beginner bikes. I am mostly concerned about the jump from whatever "beginner" bike I get to a more advanced 600cc bike. I feel like the jump from the venom x22 to a 600cc might be too much but if I can save the $2000 difference between the venom and the ninja 400 for a bike that I plan on outgrowing within a couple years it might be worth it.

Does anyone have experience going from an underpowered sportsbike like the venom to a real deal sportsbike and if so do you think its worth paying more for a bigger beginner bike (or buying a used 2-4 year old beginner bike with more power) just so the change to a 600cc is less jarring?

I probably sound super cautious but I live in wisconsin so I've got like 5 months before I can even take a msf course and start riding so I just want to do a bunch of research and make the best decision I can for me.

Also sorry for the long essay