Bicycle Mechanics - help out a beginner- can't pedal forward

Hello everyone-
FYI I am a complete beginner when it comes to anything related to bikes. The other day I was trying to clean and lubricate my chain. Everything seemed fine but when I went to ride it the pedals wouldn't turn forward. I can backpedal fine, and when the rear wheel is lifted off the ground they can turn both directions. It seems like something about the pressure of the ground pushing up on the wheel prevents the cassette from turning forward.

I am getting ready to take it to a shop but I won't get a chance for a while and I thought I would try to figure out if there is a relatively simple solution (or at least figure out what I did!) first. My apologies if this kind of question has already been answered.

Thanks!

Does the front wheel spin? Is the rear hub tightened correctly? Can you post a video of you trying to spin it?

Yes.

you may need to shift it out of the 53-11 to be able to pedal.

you may need to shift it out of the 53-11 to be able to pedal.
ha, that's what I was thinking.

If you want some help, you need to either describe the problem in greater mechanical detail, or post some photos. Since you say you know almost nothing about bicycles, you probably should post some photos or video.

Thanks everyone for the responses. I was able to try shifting into a lower gear but that didn't make difference. I think the rear hub is tightened ok, I actually tried loosening it a little and that didn't do anything so I tightened it back to how it was. I might be able to get some pictures up this evening.