Hi and welcome.
You are a member from Mexico and it would be interesting to learn from any responses how many more Mexican readers we might have.
The Speedo Fantasy Board has been gone for some four months now and this is what we have in its place.
You will have had a flavor of the posts submitted from what you have seen already and the technicalities of navigating the site are explained for new members in the stickies posted by our Moderator Mike.
The Forums are as follows and the descriptions pretty much explain themselves:
Swim Suit Forums
general swimsuit guy talk
buy or sell announcements
story center
puzzle center
Lycra Forums
general lycra chat
buy or sell announcements (empty)
Off Topic Form
off topic chat and discussion
The destination for your post(s) should be chosen accordingly and it will no doubt be obvious that most new threads are started in General Swimsuit Guy Talk.
As for being big you may judge for yourself what reactions there have been to pics posted of big (or small) guys in great physical shape and wearing some very attractive swimsuits (I will not say speedos there). If your username is Chubby it is possible that there would be less adulation of that kind but that is no reason to suppose that what you might wish to say is of no interest
(and the same applies to age).
I guess the only "qualification" required of a poster is to be a speedo and/or lycra lover - so "suck it and see" and good luck.