Something very important to remember is that a person needs to look at where their teacher has studied, with whom AND how their character and manners are. Everyone has flaws, without a doubt, but are they generally poorly behaved? Aggressive? Quick to give fatwas?
Today, people take ilm from others and don’t know anything about them at all! Or someone who’s studied a little bit of Arabic in Egypt for one year and he’s now a big sheikh?!
As an example, a sheikh has studied the Islamic sciences for 20 years, mastered a lot of them and now teaches.
Check who they are and what they are like.