Acquiring hosting is straightforward. Pick a company with a good reputation, a reasonable price, and all the features you need, sign up, and pay. (I can't be of much help here, as I've used the same hosting company since 2004 or so, and I'm not sure if I could get a better deal elsewhere.)

The remainder is more specific, and that might be why you are having trouble finding tuturials. E.g., uploading and setting up a wiki could mean you read tutorials on SSH or FTP, tutorials on file permissions, and/or tutorials on the wiki-specific details of setting up a wiki. All of this depends on your experience level. When I started out, I knew none of this, and I basically figured it out as I went along.