There is nothing true 100% of the time in Go and a lot of things you “learn” not to do can later turn out to be playable in the right situation and vice versa. I urge you take every advice you can get but not blindly. Use any advice of a stronger player but think about why and when.
Every player is different and yet a lot of the mistakes repeat. A clever man learns from the mistakes of others, so check out what I did wrong when I was starting
Do not try to kill EVERYTHING - do not be too greedy. If you attack everything it usually means you are also leaving weaknesses everywhere and your whole position may crumble. Both players have the same number of moves, your opponent is also entitled to make points. You only need to get a little more than your opponent every time.
Do not be a puppy - do not just follow your opponent around answering everything he/she does. Look for a time to take the initiative and try to keep it.
A bad move is a punishment in itself. - often times people ask, I see my opponent made a mistake in the opening/in this position in his/her shape… How do I punish? And often times the answer is you do not. A bad move is bad in itself. It is not as efficient, safe, or whatever… Play like you normally would and the problem will eventually reveal itself. If you go out of your way trying to immediately punish and destroy, chances are you will make an even bigger mistake by being too greedy and creating weaknesses for yourself.
Let me get back to this one later