There are many potential altcoins, you can visit coinmarketcap. Currently, I advise you to start investing with Ripple / XRP.
In addition, you can also try ICO. Buy at pre-ICO prices, if lucky when launching in the market price can exceed ICO, can get profit doubled.
Right. The top ten coins would be your most logical choice since they're pretty established though it won't hurt if you set aside a few bucks to try your luck in icos and lesser known coins. Its a volatile market. Small coins can pump up to more than 100%. Research and study is your best tool dude