I’m not good at Mula Bandha (root lock) and know I should practice it in order to improve. First step taken, I did a little research and found some useful posts about it.

A Beginner’s Guide to Mula Bandha (Root Lock). Tone your pelvic floor and improve your meditation by practicing mula bandha (the root lock).

Using Mula Bandha, the Root Lock

Yogi Secrets: Bandhas which is about the 3 main bandhas.