depends on what specialization
>party/club DJ
easiest. Just about reading the room and pleasing the audience. If noone is doing the chacha slide, you transition. All you really gotta do is transition. This is where the jobs are, you can maybe do some local parties
>skilled DJ
people listen to you because you scratch or mix really well (or not, they just listen to party dj)
>underground DJ
you collect tons of obscure music that goes together well and play sets to people who like hearing music they never heard before. don't get paid, but passionate about the obscure genres you obsess over (i will listen to you)