Canon T3i Rebel does not autofocus in video-recording mode so right before starting to record a video, I would like to position myself in front of the camera and autofocus using the AmazonBasics Wireless Remote Control. How can I achieve this?
I could be wrong, but my understanding of the AmazonBasics Wireless Remote Control is that it is only for remotely controlling the shutter (i.e., it only works for pictures). In photo mode, it will autofocus after you press the button. One thing to test would be to try enabling autofocus on your camera/lens, starting recording, and stand in front of the camera. Use the shutter to remotely take a picture (the T3i can take pictures while recording). After that, your autofocus should be set.
Once again, not 100% sure that this would work, but that is what I would try first.
I'm assuming this is the standard EF-S 18-55mm f/3.5-5.6 IS Type II Lens that comes in the T3i kit? You're either going to need some kind of adapter that sits between the lens and the camera body that has logic circuity in it to allow you to remotely adjust the lens, like this puppy (note that is meant to also adapt EF lenses to E bodies, so that's not the exact unit you'd want to buy) or you'd want some kind of Follow Focus system with a cable "remote," like this. Again, this is just an example, so you'd want to shop around and make sure you find one in your price range and are sure is compatible with your lens.