I know that my ISP doesnt give me public IP address, so it's hard to self host anything, because my IP is not accessible to the global Internet. But at least,

I know that my ISP doesnt give me public IP address, so it's hard to self host anything, because my IP is not accessible to the global Internet. But at least, can my IP be publicly accessible within the ISP's internal network? So, it's a small scale intranet of people who use the same ISP service as me. I'm still struggling to understand how computer network works, so i'm still unsure whether this plan is feasible or not. If this plan is feasible, i'm looking to work on several p2p projects. For example, a web app that you can serve directly from your phone. So i dont have to pay my monthly server hosting fee anymore.