Whenever you play someone head to head, whomever is hosting might have a FIREWALL setup.
Even basic computer setups usually have the Windows Firewall up.
You need to enable the Gens program to be allowed through the firewall. It's the most common reason I find someone can't host. Usually, a new player is able to connect to a veteran's game via Hamachi, but struggle to host it the first week. 2 new guys is almost a guaranteed struggle.
Follow the steps to be on Discord so you can be talked through it while you are actually trying to host with your friend. Have both of you on, and you both can be chatting inside the NHL94 Discord forum and one of us will usually be around to help.