To this day, every time I have to ask when an institution or store is open, I am agonizingly unsure which word to use. Aufmachen, öffnen or offen or geöffnet? Or, to be sure, just auf? What difference between öffnen and eröffnen?
Also aufschlagen, andrehen, aufschließen can mean “open closed”. Let’s start with them, so as not to get in the way.