some questions

hello,
I have questions from beginner to do.
I'm new to this game,

I played for some time in World of Warcraft and now I switched to Final Fantasy,

there is the possibility of making "Dungeon" with other players? how do I?

sorry for my english, I'm Italian!

Do you mean playing through a dungeon with other players? Once you hit level 15, you will unlock your first dungeon, which you go through with 4 players. You can either queue up to be matched with other players, or form a group of players on your own server to enter with.

Just keep doing your story quests (the ones with that wiggly mark around it) and when you hit level 15 you'll be able to do your first dungeon and use the dungeon finder. That will let you que up for dungeons anytime anywhere you want. Just learn how to play a little first.

I have one other question.

I did a 30-day subscription,

I want to play these 30 days paid, but how do I remove the automatic renewal? I can choose how many months each play?
I paid by credit card.

You can remove the Automatic Renewal at the Mog Station, the place you went to pay. Look for "Cancel Automatic Renewal" or similar.

This morning I had a mission with other players via the "Party Finder", but now I do not do anymore, why? now is not enabled button

I believe to list a party in the PF you need at least one class to a certain level. But to join one you can be any level as long as you fill the requirements set.

At your level, you would have used Duty Finder, not Party Finder. Party Finder is unlocked later. Duty Finder is what gets you into missions.

If you want to undertake more adventures with other players (at your level that'd be Guildhests, and soon your first real Dungeons), just pop open the Duty Finder!

are now level 14, in addition to doing quests and party, how else you can gain experience?

because now all missions locked and I get to level 15 to unlock a.

you can work on you huntlog you get good xp from that