Two things ,

I fly mode 4 (aleiron on left with throttle ) I do 3d but will this stop me from progressing more ?

Second thing- what’s the best way to join a team ?

They ask you to join, mostly by being seen at events both flying well and carrying yourself well

Mode 4 is mode 1 switched... you are at an advantage over mode 2

Oh ok thanks most people said it’s harder

It's harder because people, especially in the US, aren't used to it. Otherwise, whatever works for you