I use deemon to download my music from Deezer (free account only supports 128kb/s, this is enough for me though).
For the music server I tried both Jellyfin with the Finamp app and Navidrome with the Tempo app on Android.
For desktop app for both I use SonixD/Feishin (crossplatform)
Both where fantastic solutions but I stuck with Navidrome as it was easier to share playlists. (As an URL for non registered users or as public playlist for all registered users)
My setup is as following: Hypervisor: Proxmox VE NAS: TrueNAS Scale (where all music is stored)
1 LXC container with Deemon installed that downloads music in mounted NFS share from TrueNAS
1 VM with Navidrome installed in Docker with the music folder mounted with NFS
You don't have to use such a setup, you can perfectly do this on your existing PC with Windows, MacOS or Linux with DE. Or server OS like Linux with CLI, OpenMediaVault, TrueNAS Scale or unRAID
You can use Universal Android Debloater. Most apps have a description of what it does and if it's safe to remove or not. Already debloated a few Samsung phones with it, works great :)