Totally, there's more material out there than most people expect, and some of it is surprisingly usable if you enjoy nerdy reconstruction work.
A handful of franchises actually give you something close to a 'language of dragons' that fans have turned into dictionaries and phrasebooks. For example, 'Skyrim' includes a full dragon tongue—Dovahzul—with a consistent lexicon and syntax that the community has fleshed out into online translators, pronunciation guides, and even tattoos. 'Dungeons & Dragons' lists Draconic vocabulary and bits of grammar across editions, and enthusiastic players have compiled glossaries and scripts for roleplay. Christopher Paolini's 'The Inheritance Cycle' offers the Ancient Language with strict rules used in the story, so readers have created learning sheets and cheat-sheets for spells and phrases. Outside of those, many shows and novels include dragon words that are fragmentary, so fans extrapolate grammar and meaning.
If you're trying to 'translate' something, expect to do some interpretive work: most dragon tongues are partial, and canon often leaves gaps. Good resources are fan wikis, Reddit threads, and dedicated Google Docs where people correlate text from books or games to create usable vocab lists. I like bookmarking a few reliable pages and then testing translations aloud—partly for fun, partly to see where the gaps are. At the end of the day, it's as much a creative exercise as a linguistic one, and that makes it oddly satisfying to tinker with—I've gotten a kick out of turning a two-line shout into a full sentence for cosplay and it felt delightfully ridiculous in the best way.