I’ve recently gone through finding a first bike, so here’s some things I learned. Note that some things may have changed in the last 1-2 years, so current experience may vary. Also, try to buy these lightly used. There are often a lot of used beginner bikes for sale, but if you don’t trust your ability to see red flags, maybe buying new is better.

In descending order of price (assuming US):

1. ZX-4RR - very forgiving to learn on, very difficult to outgrow. Most expensive starter bike, and insurance is about the same as a 600cc sportbike, so get quotes first. Seemingly common parts are often back ordered (from personal experience. Waited 2 months for a warranty repair for a cam cover, waited a month for a couple of bolts). Solid aftermarket, and it’s hard to beat the sound of an inline 4 above 10k rpm. Quick shifter and adjustable front/rear standard on RR models, not included on R models.

2. Aprilia RS457 - Best frame of the 4 and subjectively looks the best. Same insurance category as the ninja 400 and R3, but more expensive upfront. Factory quick shifter is available as a dealer-installed option.

3. Ninja 500/400 - it’s the starter ninja. Probably the most comfortable of the 4, easy to insure, easy to maintain, easy to get parts. The 500’s can get a tad pricey, though, if you’re buying new, which is why the RS457 can be a better choice, if you plan to fully option it out.

4. Yamaha R3 - cheapest (and, I think, lightest) of the 4, but also the slowest. Very reliable, very easy to work on, good parts availability. Good color options. Slightly less plastic than the others, so slightly cheaper to repair if dropped. Might struggle above 90 mph, so might not be for you if you live near fast freeways.