I don't plan on having more than 7-8 services running: Immich, Nextcloud+office, firefly, audiobookshelf, paperless and a maybe few more if they're useful.
This will change when you get confidence and start realising how much good stuff is out there.
I'm a noob with this stuff who has recently self learned some of this and got a decent server setup running. Feel free to DM if you want detail about my beginner resources, how, what and any other questions.
I started with a Synology NAS. I don't know about your specific NAS, but NAS hardware can be underpowered and quickly becomr too underpowered for the stuff you want to deploy.
People online recommended a mini PC for and keeping the NAS as just a NAS. I thought I better double check what's suitable for my needs......R.Pi, DIY build server computer, NUC , Unraid, TrueNAS, HexOS, etc.
So I put in loads of work to come round to realising the initial recommendations was correct. I've kept my Synology for only NAS and use a dedicated mini PC. I've put Debian on it as my server OS. No RAID configurations, but critical data is backed up across 2 to 3 different devices and media.
Super happy (and quite proud) of my setup. It is slowly expanding.
I would recommend taking it slow, document steps you take (because you will fuck up and need to redo things), backup all important data and keep it completely detached from the devices you're tinkering with, find suitable and appropriate beginner guides. Don't go underpowered, and don't get caught up with very advanced user setups with huge overkill.
It really has been a lot of fun. Welcome inside the rabbit hole.