This really depends on your comfort levels TBH. My first NAS was a old motherboard with about 4gb of memory and a old core 2 duo cpu.

If you have any old components such as a old laptop, or a old pc, or maybe some thing like a raspberry pi you can start tinkering with Samba shares.

With a raspberry pi you could run something like HomeAssistant and setup a small smaba share. Plug a hardrive in and you have a network share to store files.

As for older pc components you can start with something like truenas, it's a little bit of a learning curve but it's a good way to tinker and slowly start to learn.

For me I run truenas for all my home NAS and media storage. On the side, another pc runs something called Unraid for services like Nextcloud and Immich to keep things separated.