> What kind of car is it? This will help with everything.
> If it seems to be related to the transmission, is it an automatic or manual? Does your speedometer work correctly? Do you have a tachometer?
> The reservoir you found sounds more like power steering or brake fluid, not oil. Althought ¾ of an inch still sounds really short for either.
If it’s a modern 4 cylinder car, the dipstick will probably be up front, sometimes they snake through the exhaust manifold, most of mine haven’t been colored any particular color that I can recall. They all have had some sort of loop at the top and been between a foot and three feet long.
Others could be slightly different, but they’re usually pretty easy to check.
Easiest way to find yours is probably just to go to google, type in ”<make> dipstick location” and then click “images”... someone probably has an image of your engine bay with a nice arrow pointing right to it. Civic example