Here is a list of several websites that I use commonly, which are very useful when studying languages. Afterwards, there is some extra free language material available for anyone who is interested.
Etymonline: If you love etymologies, this is a phenomenal site to tell you the etymology of almost any English word.
DwaneThomas.com: If you want to learn Latin, French, Spanish, German, Greek, Italian, or more about the English language, this is a great resource to use. I still use it for half an hour every day as I study Spanish.
William Whittaker’s Words: This is a Latin dictionary. It’s a bit technical, but once you figure out how it works, it’s really useful.
Reverso: This website will conjugate words for several languages (including Spanish), but not Latin.
Etimologíasdechile.net: This site is in Spanish. But if you are studying Spanish and want to know the etymology of some word, this is pretty much just Etymonline in Spanish.
If you want some extra reading material for Latin, here’s a story I translated awhile back. It’s just The Three Little Pigs in Latin. It was awhile ago, but I think the translation is decent overall.
And there are also two books that are really useful for studying Latin in general. I’ve read both of them in their entirety, and they are very interesting and educational. I have them both listed below, but just so you know, I did link them through a referral program with Amazon, so it won’t cost you anything extra, but if you purchase them through these links, I get paid 4.50% of what you spend.
Lingua Latina: Lingua Latina is the main way that I learned Latin. It is a complete novel written in progressively more complicated Latin.
Colloquia Personarum: Colloquial Personarum is basically a set of “extra stories” to go along with Lingua Latina. It’s good practice and still very interesting.