1) The league - compete for the title, I want us to be in the game for the title. So something like within 5 points of the first place in the last 3 matches. I do not care if we finish fourth or second (except a few millions, there is no difference between that), but I want us to compete for the title.
2) UCL - passing the group stage. This should go without saying, but if we don't pass the group stage, I want the manager sacked ASAP. It might happen occasionally to not pass the group stage (happened to Fergie twice in this century), but it must not be an occurrence. Past that, the more we do, the better, but passing the group stage should be the minimum.
3) Domestic cups - I do not bother too much about them. Winning one would be nice in order to instal some winning mentality and cause we haven't won something since 2017, but this is way behind (1) and (2) in my priorities.
The best way for him to gain credit would be to win the league or UCL (why not both). I think this is extremely unlikely, but competing for the title, and passing the group stage of UCL (or as a bonus, eliminating after that some big team) is what I would call a good season. Something that hasn't happened since SAF left. With the team we have, and how much he has been backed, I think it is time for that.
Oh, playing attractive football would be nice. The last time we did that was on 2010-2011 or something like that.