Why would you need to create a new forum, when TF already exists with a GB sub-forum?
You will need to do the following:
1) Purchase a domain.
2) Purchase a server and hosting space, or rent hosting space and pay for that space (Rackspace, GoDaddy, Comcast, etc all have such services)
3) Purchase forum software
4) Configure and Administer the forum software. This will require that you maintain a Site Admin. and Moderation team.
The other option is to migrate the group over to Trawler Forum, much like the Mainship Yahoo group and others have done in the past.
Either solution will not get you your content back. That is owned by the previous site owner.
TF would be happy to assist with migrating Grand Banks over to Trawler Forum.