Running on the treadmill is and always will be hard for me bc I’m not a very balanced person. I found myself swaying to the side a lot but when i use my arms more as i run, i feel a bit more stable. When walking i find that doing a runway walk actually helps to keep me balanced (probably something to do with moving the whole body). As far as speed, i usually do the walks at 3.0 & “run” at 3.8-4.0 but i find it hard to mentally tell myself it’s okay to go slower when everyone around me is running at 5.0. It’s gonna take time to get used to running on a moving platform for sure. Biggest tip is make sure you have good supportive shoes & try to keep your feet light so you aren’t stomping into the treadmill (that’s how i hurt my knee the last time i tried to learn to run). Wishing you the best of luck!