Advice: accessing home network beyond home

Hi folks, I'm just getting into this hobby thanks to the posts in this community. So far, I've installed Ubuntu server 22.04 on an old laptop and got paperless working, and I'm pretty pumped. Now I would like to access it outside of my home network on my phone.

I have a Netgear R7000 with Advanced Tomato installed. Here's my plan, but I don't know if it would work... So I'm hoping for a peer review of sorts.

• Get openVPN working on the router as a server.
• make a certificate for my phone and use it as a client.
• use my fedora laptop as the CA (?).

I think I need to use easy-RDA to make the keys and certificates...

Does that sound about right? It's this a good approach or is there something better/easier/more effective?

If there's a great tutorial around for accessing the home network externally, I'd super appreciate it. Would obviously prefer to do it myself and not pay for a service... I've been enjoying the learning experience!