A question, how did you know you were on target, I ask having never shot one myself? Can you make anything out in an individual sub on camera?
That is one of the tougher things to do when starting out and if you don't have advanced systems that allow platesolving. What I used to do is to find my way to a bright star so I could get focused first. If your mount allows it to sync to a few stars to get itself aligned, this would be the time to start that. Of course you could also do that visually as well.
Once you have the scope aligned, you slew to where the object is and take a sub. For a beginner, you should start with bright nebulas/galaxies, and if you have decent focus and at least 30 seconds on a sub, you should be able to see something. With luck, you will have at least part of the object in the frame and then it is an iterative process to get it centered.
This can take some work depending on the accuracy of your mount. I did it for years and I can attest that a modern mount that can platesolve is a big game changer!
If you are taking your first shot at this time of year I would go for M31as it is huge and hard to miss.