First of all, you really need to stop skipping English class. Punctuation and paragraphs are something you need to learn how to use. OK now that my eyesight is back after going crosseyed reading a wall of text.
Personally I think its too hard to tell. I think a lot of girls read to much into a guy checking them out. I got knews for you, I'm checking out just about every girl who isn't repulsive that I come across in public. I'm a guy, its like being a dog and having bones walking all over the place. Just because I'm checking you out doesn't necessarily mean I'm interested. It simply means I find you at least a bit attractive and feel like treating myself to some eye candy for a couple seconds.
I also think that him moving to machines near you was just coincidence mostly. Only pathetic guys seriously walk around the gym trailing girls they like and pumping iron in front of them thinking it will score them a date. At the very least, he simply might have been looking for an internal ego boost. I think just about every guy is guilty of making sure any hot girl in the same room as them sees them lifting weights. Again, not a sign of interest, just a sign of a guy acting like guys do in the vicinity of women.
Most likely he at least finds you attractive which is half the battle right there. Your odds are probably 50/50 at least. However, it doesn't sound like this guy is about to make his own move so if you want to go on a date your going to have to take more initiate than just smiling in the doorway.
P.S. "Also he just had a birthday so when he opene the door for my mom and I again I smiled at him and told him happy birthday he just grinned at me for a few seconds (I think we had a moment )" -- Just want to say this made me laugh. Really allowed me to peer into this fantasy lala land you girls live in sometimes.