If you have a decent weapon for index, bring a tanky frame. I recommend wukong, as you get 3 extra lives that dont force you to drop points, and his cloud form is good for getting to the goal quickly. Another option is to play gara. Build up damage on your glass armor and you will both be hard to kill, and kill everything just by touching them. Also you can set up a wall at the enemy goal post
You can get amps from fortuna, after maxing out the Solaris United rep. That's what I did because I didn't like the idea of having to either get carried or pick up tons and tons of cores on the plains
Get the Braton and Lex prime. While not the best weapons in the game, they are still good... and most importantly, really easy to get.