Once you have mastered the Pass Line bet and the Odds bet, there are lots of other online craps bets you can add to your repertoire. There are Don't Pass Line bets, Come bets, Field bets, Hard Way bets, Any Craps bets, and more.
The important thing is to not feel overwhelmed. Just relax, take it easy, and learn each of the bets one at a time. Alternatively, you can just stick to the Pass Line bet and have a great time playing online craps for the rest of your life with that one simple craps bet. The choice is yours.