I am interested on joining a game jam but what should i do to prepare for the upcoming scream jam?

Also the only game engines i can work with is RPG MAKER MZ and Renpy, Which i have just started learning them...and have no experience...

I would recommend using godot it is really easy and i learned almost anything about 2d and if you are talented you can do 2d horror games

if you are interested in making a 3d free roam USE UNREAL there are plenty of templates and unreal already does the walking part for you lol