Hydr lifters, adjustable roller rocker arms, had some noise, tried to adjust preload did i mess up?

Buying new lifters probably won’t do anything for you but introduce real risk of serious damage. You will have to break in the new lifters to tge old cam. You would have had to seriously misadjust them to really hurt something in a short period of time and it would be obvious. Follow PRH’s advice on adjusting them. If you do, you can have confidence it is correct and the noise is what it will be. I have been down this road. When I had a hydr I did it like 6 times. I was looking for a more “precise” way. I was never happy, it always sounded like a sewing machine. Finally set it and I didn’t care what it sounded like, because it was correct. Went solid after a bit and will never put a hydr cam in anything.