Basically, any of the really common verbs we don't even think about. The most notorious one is "to be," or its forms like "was, is, were," etc. Instead of using easy, common verbs like those constantly, spice up your writing with words that have more action and interest behind them. I.e., the difference between:
"There was a loud commotion coming from the bar. Many people were hoping to see what was going on."
versus:
"A loud commotion came from the bar. Many people hoped to see what was going on."
The only difference between those sentences is replacing "was" and "were" with the other verbs in the sentence, "coming" and "hoping." Also notice that despite using "hoping" in the first sentence, putting the "were" before it sounds a more passive and overall worse. He's a site I found that can probably explain it in much more detail than I can:
https://gsediting.com/2020/04/26/how-to-avoid-weak-verbs-in-your-writing/ . There are others, but the bare basics is that if you have two verbs in a sentence talking about the same thing, you can almost certainly drop one of them. The article goes over weak verbs, and also gets into the golden rule of writing: show, don't tell.
I unfortunately don't have the time currently to look through the other doc at the moment, but I'll be sure to give it a glance once I can. Like I said before, it's all about practice and really about toughing it out and slogging through the endless number of edits before you have a final product you're happy with.