It all depends what's your 1st task.
- For 4th rank task you just need to screenshot your "main level" which is reputation level with engineers faction, just click your nickname from garage and it should all be there, or just do the screenshot from the main garage view itself.
- If you've got task about winning battles you can find it by clicking on your nickgame in top right from garage, then click on medals tab and go to missions (I believe it went like that) then there will be some kind of achievement with red ribbon as logo, which shows amount of battles you've won.