The telescope wont be drawn in 1 point perspective because it simply does not fit the requirements (vertical and horizontal lines at 90deg), it will be rotated into its own perspective grid. I would recommend just leaving that out for now until you are doing the later perspective classes, and then add it back in.
The round objects that you have chosen to include on the floor and the cauldron are not drawn properly in perspective for the vp that you have. Perfect circles drawn in 1 point perspective on any plane besides the rear wall x-y plane are surprisingly complicated things to deal with. You have to establish and keep consistent what is a perfect square at all z depths of your image and then place the circles within one of those squares. It really complicates things.
Maybe just leave those out for now, or you can head down the rabbit hole of madness (I recommend it, its fun down here.... we have tea...) and start watching more videos about it. Here is a pretty good one https://www.youtube.com/watch?v=nwBVKdd6efs
And I know that Marc goes into it in one of the classes, and on some of the streams, you can look there as well.
And the last thing is that the deer head that you have mounted would still have depth, so you would have to draw all of that out, again a very complicated thing to do. Go for it if you want, but you can also wait until I want to say term 5 when animals come into play.
If you want much more detailed help with this, and of course the paint-over, I would recommend you put the image in the Saturday Facebook stream and Marc will point out issues and solutions in real time, super helpful.
I really did like the initial room that you were using from real life. It might be simple but it really is a great study for 1 point perspective.
Sorry about the long post, keep at it!