Ignorance is no excuse… but I accept your apology and trust that now that you are armed with better information, you’ll not make the same mistake again.
The cultures of the Fae are very different as well. The main three are Winter, Summer and Wyld- though there are of course subsections to each of these, and many other subcultures besides (Elementals, for instance, rarely participate in Court politics and prefer their own company instead, usually). There is evidence that there were once Spring and Autumn Courts, with all the trappings to go along with them, but no longer exist— possibly absorbed by Summer and Winter respectively…?
Creatures of all types can belong to either Court by swearing fealty to their Queens. Most will generally pledge their allegiances in accordance with their family traditions. This is how you have trolls and ogres and goblins mainly belonging to Winter, but nymphs and centaurs in Summer, almost exclusively. Other groups, such as the Wee Folk, choose based on other criteria, some of it seemingly arbitrary (“Mab’s shoes were so soft they did not crunch the snow beneath her feet so I will pledge myself to her”, or “Titania’s hair shone like a river in the sunset, so I swear fealty to her” or “Someone has fed me pizza.”).
Changelings are also free to choose, though most that do chose Faerie chose to join the Court of their Faerie parent. There are a few notable exceptions— perhaps more famously being the current Lady and Knight of the Summer Court; changelings both, with parents of Winter, who are now presiding over the Summer Court.