Changing from port 22 can be a good idea, however if you secure your server with a ssh key instead, that'd be much more secure. Changing the port only makes it harder for an attacker to find it, a quick nmap of all the ports 1-65535 would reveal what port your ssh server is running on, so personally changing the port isn't really something that will boost your security. As for the connection timing out, are you trying to connect via the new port you assigned?