Can I have some help with a team?

For arena?

If you want the most points with a somewhat balanced team go Marth/Eirika/Ephraim/Fae.
If you want a more balanced team but with less points you can run Azura/Linde/Camila/Eirika.

You are going to get quite a significant amount of more points with the first team but its going to be harder to get flawless wins. When the arena resets in two days the bonus heroes will change so you will also have to adjust the teams.