for testing just set all chains to allow and flush all the rules. then ping the wireguard ip of your vps from your home server (the one where wireguard is configured). this should work and should tell the vps where it can find the other wireguard endpoint. pinging your home server from the vps should work now. if this makes the connection work properly look into the wireguard keepalive settings and make sure that your home server regulary announces itself to your vps.
after that reload the netfilter/iptables on your vps.

you don’t need a firewall management tool, as long as there are no services running on the public interface there are no open ports that would need filtering.