Hello Everardo, Good luck with your search. Here is some general advice.
1) Ignore the star rating. Almost every tutor and teacher gets five stars.
2) Look at the average number of lessons per student. Some teachers make a poor impression and students stop after a few lessons. Other teachers provide value and students keep returning. When I take lessons, I look for teachers with an average of at least 10 lessons per students.
3) Look at the reviews. If some students have taken 20, 30, 40 lessons, that is a very good sign.
4) Look for training such as CELTA or TESL. Just being a pleasant person isn't enough. I have had some terrible Persian, Ukrainian, and Spanish teachers who had university degrees in literature, but who had no training as teachers for non-native speakers.
5) You can use search for teachers by time, by price, and by keyword.
Good luck!