I was really just following the script as I've never had anyone else write for me before, and to be honest the beginning had potential but I have no clue how to add suspense
You're thinking about this the wrong way. There's not much to build suspense on as of yet as there are no stakes raised as of yet.
https://www.youtube.com/watch?v=watch?v=E8AXd1ayxrg
Take the very opening shot of Orson Welles' "Touch of Evil". If they simply skipped the first moment, the bomb being set and planted, the scene would have been just two characters wandering through the street near a car until an explosion happened. But instead, with the stakes raised in the first few moments, the rest of the scene is spent holding on to the edge of your seat.
That having been said, I really don't think you need much suspense in this particular short so much as you need to jump into the meat itself. Let the fact that the clones themselves exist be suspense enough from the driving question of
why they exist.
I would really like to fix it but it is really too late now.
Why's that? Productions do re-shoots all the time. I'd recommend giving it a shot.
As for cinematography and sound, as long as I'm behind the camera I'm not bad,
Yeah, the setups weren't bad, but I would challenge you to put more thought and control into your lighting. You can actually get a lot done with just some aluminum foil, some wax paper/freezer paper (for diffusion, a few work lights/house lamps, and some foamcore boards for bounces and flags (you can also put some aluminum foil on one of these for a decent shine-board, as well.
Well thought-out lighting can really amp up production value.
https://www.youtube.com/watch?v=watch?v=sMih25gEu8A
Not the best example (considering the production value still looks to be around $0), but here's a short that I did for a competition that sprint was doing several years ago. I had zero access to decent equipment at the time, and lit everything with two house lamps, the light of the fan, and the common household stuff I listed before, and shot on a crappy little mini-DV handicam. For the closer shots I slapped some of the diffusion on my key to soften the light as much as I could manage, and set up a bounce to try to give some more flattering light from underneath.
Certainly not anywhere close to theater quality,
but it worked well enough that you might not have been able to tell that half of those shots were filmed in the middle of the day...
as for the audio I tried to use the denoiser on Adobe Premiere but I've no clue how to kill the background noise.
I'm assuming you got T2I onboard sound? Pretty much any of the audio guys in the forum will tell you, that's not going to turn out well no matter
what you do. Barring having a better option, though, you might want to consider
adding noise. Record a couple minutes of relative silence in the middle of the room, and put what you get in the gaps where there's no sound. Once it becomes the norm, the ear will adjust a bit, and focus more on the dialogue than the hiss.
Also notable, during the last shot my T2i sensor was overheating, any solutions?
In this instance? You might just need to give it a break as necessary. Make sure that the room has decent circulation, etc.