We all know to connect to internet you’ll need an address like 2001:x** or 192.x**.
Wrong. To participate on the Internet you require a public IP address - any address not reserved from public use and usually provided by your ISP.
If you locally use a private IPv4 address (from 10.0.0.0/8, 172.16.0.0/12, or 192.168.0.0/16 per RFC 1918) that address must be translated to a valid public IP address using source NAT before being sent to the Internet.
Using a vpn, while it does encrypt things and mask your IP, it still returns an IP.
You seem to mean a VPN service that provides you with another public IP address, different from your ISP's. "returns an IP" address seems to refer to "use a public IP address that's visible to the outside" - yes, that is required for Internet communication, see above.
Normally, VPN links provide private and encrypted links across an untrusted network like the Internet. The tunneling is also used to transport incompatible addresses (e.g. private addresses over public address space).
What I want to know is: is it possible to hide an IP behind an encrypted string like ; 0xFF7mXeFxb55klKEzVcb27
No. IP addresses on the Internet cannot be encrypted in any way. A packet's source IP address must be valid to the destination in order to return a reply.