I put FPs on a building through a swap thread. Now I don't know what the next step is. I thought I was supposed to put my own building in the message area, but that's not it. So after you put FPs on the last building in the thread, what do you do next?
In most guilds you post your building after the last building in the thread, and someone else will add FP to your building, post theirs, and the cycle will continue. If this isn’t the case in yours, asking a guild leader will answer your question.
With that being said, I wouldn’t recommend you to use guild swaps. The probability to get rewards is low, especially for new players with low FP income. Also guild swaps are easily abusable, especially by larger players at the expense of players with smaller FP income. I would recommend you to find someone in your guild or on your friends list to do a private FP swap between two of your GBs. In this way you will both be almost guaranteed rewards.
In the long run, I would recommend leveling your GBs with 1.9 contributions from guildmates with lv. 80 arcs (if your guild doesn’t have a 1.9 thread I would advise you to find one that does). Reason being, is that 1.9 is much more efficient FP wise than swaps. But until you build up a solid inventory (enough to snipe for the prints you need and for FP profit), private swapping would be your best bet.