i learned on an 89 ninja 600R. non-aggresive riding position, got out of its own way but not crazy fast.
And i agree with ugososlow, if you’re already planning on dropping your bike dont start lol. Im not saying nobody does, but if you dont have the confidence in yourself to keep control, then i wouldnt recommend doing it.
But to answer your question, you can pick up a late 80’s hurricane or ninja for under 2k in good condition. Or even maybe learn on an 80’s asian cruiser. Those go for almost nothing now. And they’re dirt cheap if you need parts