Also, depending on how fast you're levelling, it might be worth just getting dungeon gear/quest gear - especially if you go into the Hall of the Novice at level 15 (the Smiths in most inns will tell you about it, it's outside Aleport in La Noscea), that gear is good for a decent while. If you join an FC that puts up levelling buffs, and eat food, you'll probably stay pretty far ahead of the MSQ anyway.

Tridus covered the seals info, so there's no need to repeat it, but I will say that getting to the point where you can turn in dungeon (and other unwanted pink/green/blue) gear is a godsend when you're trying to farm seals. Especially if you decide to do a fair bit with retainers.

As for FCs, good luck! I suggest checking out Odin's server page, it looks like there's a list of FCs recruiting. I hope you find what you're looking for, and welcome back