1. Play and have fun. You won't stick around if you don't. 2. Tsumegos, most important are the tesuji and life & death when beginning, opening/ending don't matter when a blunder kills half the board. See https://goproblems.com/

If looking for a book. Cho Chikun's life & death corner problems progress in a systematic manner from beginner to dan level.

Also https://senseis.xmp.net/?LoseYourFirst50GamesAsQuicklyAsPoss...