I recently got into faery magick and I created a little faery house. It has its own little bed, and a little feeding tray with offerings in it. I dont know what to do now. Is there a spell to invite them or?
Just let them come to you. I often say offering for the fae,when I leave them something. Make sure to remove the food after a day, sometimes you may find the food offering gone, but most of the time they feed of the energy. Keep the place clean for them, but yeah it should be enough.
There really is no spell to invite them. You can do so by, as previously suggested, setting up a special area for them. Leave them offerings, place up items they find appealing (wind chimes, small bird baths, shiny objects like colored glass globes), and by planting a few flowers that they favor. Generally anything sweet smelling seems to be a favorite. Violets, foxglove (which can be toxic, so be careful when planting and handling it), sweet peas, etc. If you feel you need to, you can write a small prayer or chant to invite them, but really it's a waiting game from that point on. If they choose to come to the space they will, but it can take time.