You can be Mr. Fix it, take the whole thing on and try to fix everything, buy new equipment, and try to solve every problem. I have interacted with many folks trying to do this in organizations and too often they end up in a pile of gear with no money left and nothing really solved. If it is personnel and teams they are trying to fix a quick repair and gut can really mess things up. Many times as a new comer you may not understand the depth of what has gone on and what is happening and may end up damaging relationships beyond repair when you need them the most.
You can settle in and leave it. Its very easy to say everything has been broken, it will always be broken. It's easy to leave relationships as toxic even when you are seeing them with fresh eyes from the outside. To become the NO man, and the we could never do that person and just ride things out is one of the most toxic directions you can take in an AV department.
So if fixing everything doesn't work, and leaving it all alone doesn't work then what can you do? The answer I believe is to reach out for some trusted help and build a plan. These words are funny coming from me because I am one of the least patient people alive but it has shown to be a very functional approach. Step one, phone a friend. This friend doesn't have to be the end of all AV knowledge or even a professional but someone trusted to help you think through things. If you are working in a new organization maybe even choose to reach out to a co worker or boss. Asking for help not only helps you build a relationship, but helps build a team, and can help someone else in the organization to stand with you.
Once you have a team start building a plan. One of my first recommendations in building a plan is to identify the goals of the project in detail. Write them all down, even current already accomplished goals. Start with things that are as simple as "we need a way to plug in a laptop on stage", and move to things like "lighting is too dark". Speak with everyone involved as you may encounter goals important to others like "we need lighting darker in the control area but brighter in the overall auditorium". Once you have goals you rank them by most important or most time sensitive. After ranking, you can present possible solutions.
When identifying and presenting solutions look at the scope or "size" of the project. Is this a multi person or multi department project? Is this project going to require a lot of funds? Is this solution needing to be accomplished on a short time table? Once the scope is identified I like to pick a large project on a larger timeline to start plus 2 or 3 smaller ones. The large project will take lots of thought, people, and possibly funding so you can't do it all at once, it can also get overwhelming if you focus on nothing but that project. This is where the small ones come in! Little things you can finish quickly and easily for noticeable benefit! Little encouragements along the way. Its a great idea to take a break from a project like changing the lighting design in the main auditorium to do a small one like organizing an AV closet for easier access. Finishing the closet makes it easier for you to work, and gets your mind off the big lighting project so you can come back in a day or two fresh!
I hope this was helpful and please remember reach out if there are any problems that Lambda AV can help you to solve!