Always invest what you are prepare to lose - if you make bad decision - loss is than what you expected to lose, if you pick good project and make profit, its like you win in bet - happy times.
Big coins are not sure profit, try to find relatively new coin , deployed in last year or two, with stable price and launched products - usability cases. I found one 3 months ago, and i am sorry that i am not there from start.
https://imgur.com/a/qFIjyBJGood luck !