I was also considering getting a tutor from Italki to help with my Japanese. Currently, I decided not to hire one yet because I am still at a very basic level so I feel like my money would be wasted. (I’ll wait until I’m done with Genki 1/ halfway through Genki 2)
Anyway, from what I’ve heard on Reddit and other sites, hiring someone from Italki seems to be worth it. Generally, after you have booked a lesson with a tutor/teacher, you should contact them and let them know what you want to focus on and what kind of things you have studied so far. Usually, the teachers will have Japanese learning books with them. So if you’re studying using Genki, you can tell them you’ve studied up to x chapter. They should be able to create a lesson plan that suits you as well.
As far as being worried about awkward silences, I’ve heard that the teachers/tutors are usually great at asking you questions or engaging you so there shouldn’t be any worry about not knowing what to talk about. If for some reason they don’t try to engage you, you should let them know that you’re having trouble.
My advice would be to go hire a professional teacher first just because they have structured lesson plans and are more qualified at… well, teaching. Those people are the ones who actually have experience teaching and they will have a better idea on what you need to work on and also be better at explaining things.
Community tutors on the other hand doesn’t require to have a structured lesson ready. They might also not be able to explain things as clearly since they could just be native speakers that doesn’t have any teaching experience. Although, I heard they’re good if you want to pratice your conversation skills.
Also, definitely use the trial lessons that you have. You have three to use and the trial lessons are only 30 minutes long. Also, some have a cheaper rate on the trial lessons. Don’t be afraid to find other teachers if you feel like the current one doesn’t click with you.
I would also recommend looking at the reviews left by the other students, and to definitely check out their introduction video to see if you can understand the way they say things. Also even better if the teacher can also speak some English so that they can explain things to you.
Although I don’t have any experience with Italki yet, I hope that my research helps. Good luck!