ultimately, you will need some kind of access to something with at least one port open, if you intend to host services on the clearnet. you could use tor if onion services will work for you. if you have ssh access somewhere with a port open (or a friendly sysadmin), you could tunnel to there and redirect incoming connections back through the tunnel. same thing with a VPN, if the sysadmin is really friendly.

syncthing works on every device and substitutes for cloud storage services. pictures taken with a phone end up quickly in the shared folder on my desktop. etc.