Try using the NORMALIZE function on tracks you can’t get enough volume on. It also sounds like you might need a little compression on some of those tracks. There are deep lessons online about proper use of compression with various instruments, but the goal is to balance out the levels on instruments that have a wide dynamic range.
Also, you don’t need to boost things up too much for mixing. That was a lot more important with analog/tape mixing because of tape noise. Your master buss should have levels no higher than -6 and should NEVER go “red.”