make sure you have a solid diet first, then work in your supplements to help aid those goals, give you a boost pre-workout, and to speed up recovery! They're called supplements for a reason, so you need a solid foundation first.
Whey protein is a great supplement to help you achieve your protein requirements and is convenient if you're always on the go. Creatine is also a staple supp with a lot of people. It has lots of positive research behind it and is one of the most concrete supplements to take in helping put on lean mass. If you're a hard gainer, you can look at a weight gainer to help you reach your caloric intake goals, however try to get as much whole foods as possible!!
Cheers