How to Avoid Plateaus in Powerlifting?

Bigger Stronger Leaner Powerlifting & Strength Sports
1

You can’t just benchpress/squat/deadlift the same all the time do you?

What you can change ? from 5 reps 85% 1RM to 3 with 90% 1RM? / add some bodybuilding exercises? / maybe just lift from 5-6 sets to 10 instead?

Are these good enough? how much should be the periodisation in powerlifting? (each 2-3 weeks ,monthly? 2 months?)

2

Google the Conjugate System. Not saying a begginner necessarily should use it (although worked great for my wife) will answer all the questions you just asked.