Even if you don't really understand async/await in C#, you can do it mostly right by following just a few rules:
1) Make anything that accesses a resource over the network, in a database, or in the filesystem async. So basically any time you make an HTTP request, execute a SQL query, or open a file etc. Otherwise you should generally stick to synchronous since async code is actually slightly slower than synchronous code. An exception to this might be if you're doing some heavy computation that's going to take a while and don't want it blocking the UI thread
2) Async is viral. If you have a method that calls an async method, you need to make the calling method async too. You need to then make its own calling method async as well all the way back to Main()
3) Never use async void as a return type, with the sole notable exception to this rule being event handlers. Use async Task instead as the return type (or async Task if it returns a value)
4) Always call async code with the "await SomeAsyncFunction()" syntax. Calling it other ways like "SomeAsyncFunction().Result" will eliminate most of the benefits of using async in the first place since it is blocking, can cause deadlocks in some cases, etc.
Follow those 4 rules and you don't really even need to understand how async works under the hood, though personally I'd recommend learning it as it will help you a lot when you run into issues with edge cases.