Starting vinyl mixing

Hi everyone, sou I bought a bunch of vinyls and I am trying to mix them on a studio I can use. I am still a beginner but I can beatmatch almost every time by ear on digital gear.

On vinyl I tried for 2h last week and tanked every transition 😅 since there is no BPM marked, I was thinking to add some labels to the record sleeves, do you think it is a good idea? At least I know if I need to go up or down (trying to transition from a digital track to a vinyl and then out to digital again).

Besides that, any tips/tutorials would be much appreciated 🙏