Welcome Darren.
I hope you & your hardy crew enjoy True Dungeon once you get a taste of it. It's an experience like no other.
If you have a crew of 4, there's a few different ways you can "round out" your group.
One is to wait for event registration day and buy 4 tickets, and wait to see who else has the other 6 tickets (to the 10-man event). Sometimes players register, and then come to the forums to find the rest of the people in their slot, so they can arrange classes, talk about gear, etc. Sometimes they don't, and the first time you meet your party is 2 mins before the run. You never know what you'll get, but if you are flexible, this is probably the easiest way.
A popular way to assemble a team of 10 is to buy a whole slot of tickets, and then talk to people on the forums to fill the other tickets. This is hard to do, with how fast TD sells out (and a little expensive up front since you have to pay for the full run and wait for others to pay you back), but it gives you the best control over your party!
Another common way of assembling group is the inverse of the method above. Hang out on the forums and find a group which is planning to buy a full slot of tickets (or who has already bought tickets!) and join them. You have slightly less flex room for classes this way (since the ticket buyer usually gets first choice, and/or has friends who dibs certain classes) but this is a great way to meet established players, and 90% of the time you'll find experienced players who can help you out in the token department, if you want to gear up for (Bug)bear. (Thanks, cd!)
I'll repeat what others have said about tokens: The forums are skewed to a discussion of these addictive little chips, but they are not essential for a fun game. (They're just a diversion to keep us occupied during the 11 months of the year which aren't August.)