I suggest a comprehensive consideration.
First of all, from the perspective of course quality, this is the most important point. The best way I can give you is to find some free courses online, listen to them by yourself, and then find one you like in combination with other people's comments.
Secondly, if you can't find an old student from his evaluation, there is no way out. You can only look at the online comments that say you are a real student, not just optimistic or bad. You can see which one is true and which one you believe.
Then, look at the teaching staff, teachers in general institutions are similar, mainly depending on their academic qualifications, qualifications, teaching style, whether they are profound or not, and whether they are willing to answer these questions for students.
Then, look at the price and the environment, both of which are acceptable to you.
Very general, but the main points are clear. According to the above points, comprehensively consider, find a reliable one, show you a picture, and compare several training institutions (personal opinion, listen or not).