Hi and welcome!
I have a couple of different Maxillarias, but I have the tenuifolia. I keep mine in sphag moss, and I have all of mine in either slotted plastic pots or open wooden hanging boxes (for good air flow). They like to be moist all the time, and love good air flow, and like cool night temps if possible (55 to 65F). Medium to bright light. One thing about them, they really resent being repotted.
I wouldn't let it dry out much, but don't have it soaking wet either. Just keep it on the damp side in moss and make sure there's lots of air flow. It may take a while and if you didn't have many roots, it will be even slower getting going, but once it's done it's hissy fit from being disturbed, you will have a nice orchid there. I hope!
Another thing, this is not their active time (I don't believe-not for me here anyway) so that will slow it up a bit, too.