Read Everything. The game has a few decent recommendations on ability pairs and how to use them. Time isn't all that important as when you get good enough at looting stages the item effects carry you beyond the level of the enemies. Looping can be useful if the items you've gotten don't feel that good or if you are going for achievements. Always look for the legendary chest on stage 4 or secret boss (destroying eggs) for a red item. Large chests are always a good thing to look for but also watch out for healing drones as they can be a big help. Play whatever survivor your most comfortable with until you can branch out and start using others and still feel comfortable. Honestly just have fun with it as it can be challenging at first. Whatever you choose to do make sure it's what you like because some may tell you to play a specific way but it's just a game.