What I was wondering, I have a Local active directory running, and was wondering if it is possible to create a tunnel for active directory so that people outside my network can join the domain
How many users do you need to connect to your Active Directory domain controller? You may also want to check out Tailscale and Zero Tier.
I use Cloudflare Tunnels to self-host applications, but I use Zero Tier for virtual networking. You can use Zero Tier for free, for up to 25 devices. Zero Tier is ridiculously easy to set up, and they specialize in overlay networking.