When you start playing Go, you will be overwhelmed with good advice and information. Let me give you ... more advice.
1. Tactics: always read at least two moves deep. Do not assume that your opponent will not answer. If your move is only a good move if he doesn't answer, it is a bad move.
2. Technique: If after your opponent's answer your group has not many liberties, probably as many or fewer than before, then reconsider your move.
3. Strategy: Connect. Cut. Ask yourself if continuing locally is best. If in doubt, look for the largest open area.