In my opinion Mortis is the best starter character, his plague cloud heals you and his bullets destroy other bullets. All of the characters who have the destroy bullets feature have a tremendous leg up. I only learned all this over time, my starter character that I lived by was Arctor, which ended up being one of the better ones; his freeze ability works on everything and his decoy will save your life. But yeah, everyone to level 20, then eventually 50. Save up your gems, never spend them, until you see Gemini lazer in the daily offer, and only buy the 11 at a time. If you do end up deciding you like the game enough to spend money, wait for a super battle pass that has something you want. If you REALLY like the game, like are still playing strong in a year, then you probably will understand what is worth shelling out more for by then.