This is a great way to learn!

Look into Proxmox(https://www.proxmox.com/) for setting up your own ec2 like VM platform. This makes it pretty easy to experiment with setting up and running different services on the same box in an isolated way. Practice things like setting up a VM with a GPU passthrough and then running gpu enabled docker containers on the VM.

Also look into getting a Hetzner server and setting up site to site Wireguard.

FWIW you don't really need to buy a mini pc. You will learn more by doing a build. The great thing about doing something like this is that you can get old data center parts for cheap. Ex: pickup a server motherboard (maybe a SUPERMICRO X9DRI-F), CPUs, and RAM on ebay for < $300. Then put everything into a used server case with a new PSU and you can do everything for $500 or $600. This setup will have more resources then any off the shelf thing you can buy.

While I absolutely support the idea of Proxmox (especially with ZFS), I think to start a learning project it is probably overkill to spend $600. I would maybe start with a Dell T30 or Fujitsu Celsius W550 for < $100 used or using a Gigabyte MC12-LE0 Mainboard with a Ryzen Pro 5600. Stacking one of these with a modern NVMe and some ECC RAM should go for additional $200, the Fujitsu Machine is OLD, but has intel AMT Remote Management and draws <10W Idle.

I can get a mini pc for similar price range. I don't think that'd be true in Nepal(more resources than...)