It can be rather daunting for a newb if... you've little experience with forums and /or you don't meet the requirements to access the marketplace.
The first challenge will require that you get familiar with the following: a) understanding how the marketplace works(first come first serve system) and b) how to initiate contact with the seller. - There are of course other simple rules such as no commenting on price etc etc. though I wouldn't consider those difficulties.
The second challenge(as far as I know) can be dealt with in two ways. 1) you can participate in the forum until the reach the required no. of posts to access the forum or 2) you can make a donation to the site and gain access to the marketplace immediately.
PS. I haven't looked-up the rules and requirements since I joined here many years ago, and so if I'm wrong on any of these pointers please take into consideration that I was likely too lazy to verify the advice to begin with.
Hope this helps.
JohnBee