Where can I find Elvish texts and compositions?
There are many sites dedicated to post-tolkienian compositions of texts, poems and songs in Elvish. I won’t recommend any in particular, because they are too many. Instead, I will provide the link Elvish Poetry which is a (quite huge) link collection that leads to many Elvish texts pages. But you must have in mind, the post-tolkienian texts are in no way canonical. It’s a bad idea to start studying Elvish from these texts, since as mentioned, Tolkien’s languages are not perfectly understood and their vocabularies have gaps. Those works often contain reconstructed words and rules, not to mention that they must have mistakes.