Hello, I have recently began to research and have more of an interest in Djinni, but I would like to know what kind of Djinn would be best for beginners? Is there a shop or type you would recommend? I might do a reverse adoption but I would love your advice on this. Thank you so much!

Marid, maybe?
CH also offers djinn bindings : )

Marid and Jann Djinn are known to be towards the lighter arts end of the spectrum (though there are certainly exceptions to this rule!) and can be easier to handle than those that tend towards the darker arts, so they might be a good place to start. Ifrit are a nice mid point, and tend to be darker arts than Jann and Marid, if you feel more inclined towards those of a darker nature. Ghul and Shaitan make up the remainder and tend to be quite dark, and are typically not recommended for beginners (and I know those who don't recommend Shaitan Djinn at all).