I smoke cannabis ¿someone tips?

First of all, Happy New Year to everyone. I hope everything is going well for you. I've been smoking cannabis since I was 16 and I'm now 18 this year. I'm thinking of quitting on January 1st to join the Venezuelan Criminal and Forensic Scientific Investigation Corps. The thing is, I don't know if there's a drug test to join. Any advice in case I relapse? (PDTA: I'm currently studying sociology at the best university in Venezuela and people are telling me that I'd rather keep studying my career.)