If you aren't really close friends, then it's best to add -san to the first or last name because that's the most neutral and most used one.
The closer you are to the person, you can either use -kun for boys (or for younger girls, though it's mostly used for boys), - chan (for girls, or for younger boys though again it's mostly used for girls) or just the name without any honorifics because without those, it implies you're really close (don't drop honorifics when talking to a stranger, someone who is higher in rank or someone you aren't really friends with, because that's considered rude)
Sensei is used for teachers, professors and artists like mangaka and authors.
-Sama is used for people you have to pay respect to like a master in a particular arts for example.
Senpai is not really a honorific but you can call someone that when they are higher than you in school or even at work to signify they are more experienced. Same for kohai though that one is used for students lower in school.
You also have -dono if I remember correctly but that one was mostly used by samurai, so it's out of use now
