New to bodybuilding drop some advice!?

Hi well my names jack, I’m 25, 6ft and I’m 70kg... i cut down too 66kg too fight, but now I wanna pack on some muscle too my frame so I don’t look like a skinny fat slender man..

I’ve been involved with combat sports for 3-4 years, but now I’m interested in bulking up moving up a weight class. I’m quite clued up with general weight training, squatting, benching, deadlifting. Just need some good old advice I can use too help me pack on some mass fast as possible, nutrition plans etc too help me stay lean bulking.
Ps
I’m fighting August 3rd! And I’m loooking too lump come October.