Mixing Different Tempos

I would suggest the How To Digital DJ Fast course. It will take you through various effect (FX) mixing techniques, as well as using drop and cut mixing to change genres and/or big bpm differences.

Stick with themes for a while, and try to transition on something without percussion (a breakdown or non-percussive outro) or if you’re really fancy, have some handy short musical bits to act as a short bridge between records. Bouncing around genres with different tempos can ruin the flow but if you kinda do almost mini-mixes of a similar theme, that might work.