Hello I'm Mark, an adult chess improver. I like chess and play online on lichess.org and chess.com. The basic courses on here are taught well and help make all phases of the game clear. Two more tips to help during the opening would be to "deal with opponent's threats first than finish development. "Next keep the pawns in front of the king in original position for as long as possible (to avoid weaknesses around the king). " These two principles were taken from vidoes that NM Lopez gave on some online videos.