Welcome Adella. Glad you found this place.
Now for your questions. First, Tolumnia are in the Oncidium group, not Pleurothallis. This should help with culture. They are "new world" orchids found living as twig epiphytes at the top of trees in the Caribbean Islands. Thus they enjoy rather bright light, frequent wettings of roots follwed by drying, etc. They are very drought tolerant, but will appreciate a bit more water while in growth stage (sounds like yours is.) You made an excellent choice as a first if you consider the above. Light sounds fine. I would recommend a brightness that pushes the leaves to a purple color, at least along the edges. My feeling is that you are not watering enough and it may start shrivelling. It can be tricky balancing enough water with not rotting the roots. How is it potted? Mine is in really big charcoal chunks, primarily to stabilized the plant. If you water and it pours out the bottom that is OK. Pour water through the pot. Pure water like rain water, distilled water Reverse Osmosis water, is what it wants. Mine gets every other day soaking in a mix of MSU blend fertilizer mixed to 125ppm Nitrogen mixed in RO water. See
Plant Nutrition for some free info. Check the "free information" page of Ray's site for additional stuff like fertilizer calculator so you can use whatever fertilizer you choose.
For Jairak Rainbow, I trim the stalk after last flower falls. In my experience this cultivar will not rebloom on same stalk. Other cultivars may, so when you aquire others in future, wait to see what happens before cutting the stalk.
2 small fans is a good sign. These should become blooming size by next spring or late winter.
Here is link to my contribution after a year of careful culture.
Tolumnia Jairak Rainbow 'Pink'
Hope this helps and answers your questions. Once again, welcome.