Grind strikes, start with tiger until you can get to level 26 or higher and then start doing Roc. Save Vanguard marks and buy legendary gear from the vanguard vendor. You can only get 100 marks/week, but you’ll still get rare (and possible legendary) engrams from them. Don’t forget to level up your vanguard reputation to level 2 or you won’t be able to buy gear! (You’ll need a vanguard commendation to buy the helmet and chest if I’m correct so you’ll have to grind out two more levels to get those if you need to resort to buying all your gear.) Sometimes a blue engram will decrypt in a legendary item. (Very rarely and usually when that happens it will be for another class, so don’t count on it.) If you’re on ps4, I can run you through the first parts of CE to give you a chance at some raid gear, but you have to be level 27 minimum to join.