For looking to joining a Free Company you can have a look through the World Section on the forums or the sub reddit FFXIVRECRUITMENT.

Free Companies can give you buffs. Depending what two they have activated and you're missing out on that if you're not in one already.

Ideally you would be looking for a Free Company that has access to rank 3 buffs (And is usuing "The Heart of Battle 3" as a daily one) as well as a large mansion with the 8 crafting benches for your use. (These will give a bonus to crafting and make the process slightly easier. Only large mansions can hold all 8 crafting benches though).

Alternatively you have a look at the Free Company standings for your server and look at the top 100. This will give you a good indication of the more active ones compared to the thousands who are empty shells.