I want to start with self hosting something available from internet. Currently I have jellyfin, nas etc but everything is available in local network.
My biggest concern is securing local network. I thought i will run application on separate server, I will use small vps as proxy, but Im not sure if it will be enough


Yeah, but if my server is in the local network, I have potential threat that someone will access my lan through public server
Well, you could do network segmentation:
Utilize UFW rules. Mine are:
sudo ufw default deny incoming
sudo ufw default allow outgoing
Anywhere ALLOW IN 192.168.1.0/24
22 ALLOW IN 192.168.1.0/24
22 on tailscale0 ALLOW IN Anywhere
22 (v6) on tailscale0 ALLOW IN Anywhere (v6)
Also:
So now I have SSH capability locally and through Tailscale installed on the server and this prevents the server from initiating connections to other LAN devices. You can do alot with UFW and Fail2Ban in conjunction with Cloudflare Tunnels/Zero Trust.