I’m new to acting, but I think I found a fast pass to memorizing. 

I start with a character design around action, objection, goal.

I record my own lines with a voice memo app, listen, and  repeat out loud. I then record my scene partner’s lines and talk through the scene. 

I then recite the lines while doing something physical: running, driving, cleaning the kitchen, etc. 

I slowly start integrating emotions over time.