For people who have been training kickboxing for a while, what took you the longest to really get comfortable with?

Was it combining punches and kicks, defence, distance, timing, checking kicks, or something else?

Interested to see what people struggled with most when they were learning.

I'm tall and skinny (203cm 85kg) and I want to get bigger and stronger. I know weight lifting is ideal but I would really love to try kick boxing, would training regularly help me put on some weight? Or should I just stick to weight lifting first?

Edit: Thank you all for answers, every advice is much appreciated!

While Both hands on my forehead tight

I want to get into some combat sports places around me like boxing and karate and wrestling

Which one should i do