Coopercharged

I'm just re-starting back out took several years off from the hobby. Wow have things changed. So I have some old goggles fat shark transformers se, radiomaster tx16, and bought a sub250 nimble 65. It flies great but have a lot of questions as it seems really fast. Anyone have experience with these and can help. Didn't know what to change in betaflight so pretty much just set up controller bound elrs and got in air but I feel like it needs more tuning or something. I can't slow it down it's like all or nothing. Might just be me too don't know.