Hi Monica,
I do it with the windows explorer, I connect the mobile to the PC, it comes out as if it were a folder more and then you create a folder that is called music and there you put everything, although if you are going to put a lot, I would recommend using an SD .
Another option is to use a browser on the mobile (I use solid explorer, which can open two windows), because I do, one is the pc (a folder that I have shared), I move there the lp and then from the mobile , I move it to the folder of the sd, so I do not have to move from the sofa ...
Another option is using Telegram and your personal folder, there you can upload all the music you want, hahaha, although I have not told you this, hahaha
If you need more help, say so ...