How long does it take to be good enough for modeling tests?

Hey all, I will be recruiting for full time opportunities as someone who doesn't have an internship this summer, and I am doing modeling through training programs. I wanted to know how well I neeed to model for modeling exams, and what models I should focus on, I am currently completing three statement modeling, and then will do DCF and LBOs.

For reference, I have never modeled before.

This is for someone looking at equity research, investment analyst rotational programs, etc