Keep It Real...
I'll let you off because it was your first attempt, I did the same thing when I started, try and avoid stuff like 'cruising in my cadillac, got my bitches in the back'. I'm all for tracks about weed, but keep it real, relax a little when you write and don't feel like you have to fill other rappers shoes with your content. Keep it real and true to yourself throughout, and eventually you'll regret ever rhyming like some half-arsed mainstream pushover.
Put some more feeling in your voice (don't overdo it) and find your 'rap tone' and start getting comfortable with it. Attack that beat like you mean it, don't be shy.
If you need any more advice, just message me mate, always good to see now artists.