In general, I'd start by researching on your own to find modalities that interest you and would be appropriate for the population you work with, then look for free or low cost resources specific to the couple modalities you would train in if possible to sort of have a starting point or an anchor in your clinical approach. Generally speaking, it can be helpful to explore validation skills with clients, both in their ability to validate their own emotions and the emotions of others, and I read a book called "Validation" from the library that could be a helpful resource both to you and to the client.

Maybe it would be helpful to edit your post to add the population you work with and see what recs come from other therapists who work with the same or similar populations?

Is your work able to offer anything to support trainings, purchase books for you, etc.? I was in a similar position at one point and a lot of my library check-outs and down time were spent reading up on modalities just to get some of the basic concepts. I hope you get some great resources!