Hi Chino,
welcome to Ice In Space
From your description, I think John could be right about the end cap.
Note that the end cap has two sections, a larger cap with a smaller cap.
The larger cap needs to be removed.
Additionally from your description, it sounds like you may be confusing the use of the barlow. It should not initially be put into the focuser. The 20mm eyepiece (without barlow) should be used for initial operation and to line up your finder scope.
Adjusting the mirror screws may put your mirrors out of alignment, but these should not be further adjusted without some sort of alignment tool.
Where are you located?
Edit: Sorry David got in while I was still typing.
It now sounds like a focus problem.
But you may need the erecting prism to achieve focus so try both ways.
But definitely don't use the barlow yet.
You use of "lens and eyepeice" makes me think you still have the barlow in.
This would make it difficult to use initially