https://mexica.ohui.net/curso/1/ is a nice start if you know Spanish.
http://ikindalikelanguages.com/labs/lesson.php?id=264 is good since it kind of makes you use the grammar as you learn it.
Also, there are some decent Memrise lessons for it for vocanulary and some grammar if you search. Some better than others of course. You should do a Google search for that to see what you find best, since I don't know if you want to learn a particular modern dialect or Classical Nahuatl. A good "Memrise Nahuatl" would do the trick.
I have a couple other resources for it saved on my computer, but since I don't have access to it right now, I'll have to give them to you at another time.
Hope that suffices for now though.
> https://mexica.ohui.net/curso/1/ is a nice start if you know Spanish.
This has a lot of mistakes. Among other things:
I could go on...
> http://ikindalikelanguages.com/labs/lesson.php?id=264 is good since it kind of makes you use the grammar as you learn it.
This is very short and yet they still managed to include a few mistakes and a whole bunch of neologisms. Itallān for Italy? Teutontlālpan for Germany??? I sincerely doubt these are in real use.
For Classical Nahuatl you can try Michel Launey's An Introduction to Classical Nahuatl. It's an English translation/adaptation of his 1979 grammar which was written in French, and there's also a Spanish translation which was released in 1992, but these are harder to come by. You can also check out his 1986 French thesis Catégories et opérations dans la grammaire nahuatl.
Hola, creo que depende del variante que buscas aprender. Para la Huasteca, he visto que recomendan Learn Nahuatl de Yan Garcia. Para el "Clasico", quizas Nahuatl as Written.
Here's one from La Huasteca, they have different Huasteca variants I'm not sure this is the one from this post. https://play.google.com/store/apps/details?id=org.wycliffe.nahuatlhuastecaoccidental.nhw
If you just type in "Nahuatl Bible" on the Google Play store they have a bunch of bibles in different variants of Nahuatl. Also my friend who is a native speaker said the bible with his variant is 100% good.
I have made some courses if you'd like to help, but I work with modern nahuatl, not classical
The foundational text is James Lockhart’s Nahuatl As Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts..
One of my friends wrote an introductory textbook on Huasteca Nahuatl, which is the biggest variety. It's in English and it's quite comprehensive. The downside is that there's no audio.
There is an older textbook in Spanish published by the Summer Institute of Linguistics. It's also very comprehensive, but has no audio.
Beginner Nahuatl is an app you could try to use to easily begin learning on your own some basic Nahuatl words and phrases from scratch.