best party

[Vayne]

first time playing this game, which party should i use? and can u swap tidus out from main party?

[Ex-SOLDIER]

Yes, you can swap Tidus with someone else. And about party, enemies in this game can be described as classes so you will swap often to adress these enemies properly.

[Silamon]

You can if you want. Playing through the main story it does not really matter which characters you use.
For post-story content, Tidus, Wakka, Rikku, and Yuna are undeniably the best characters to use thanks to their awesome overdrives (Tidus and Wakka have massive multihit overdrives, Yuna does too once you unlock a secret aeon, wont say which since you said you just started. Rikku's overdrive just gives soooooo much utility from all the potent mixes you can create)

[Pronzayushchiy Nebesa]

tidus,wakka,yuna/rikku

[Silamon]

Just so you know, there is a certain trick you can abuse after the main story to get hundreds of levels in about 10 minutes, so you do not really have to use those 4 characters if you don't want to during the main story.