The most effective way to learn Latin is a hybrid approach of grammar-heavy pedagogy and the natural method. With this in mind, you should obtain the material of the Lingua Latina per se Illustrata series. Specifically:
In addition to the Lingua Latina series, you should also be aware of Ad Alpes , Puer Romanus , and the work of Geoffrey Steadman, who edits old student texts into a nice format with Latin text at the top of the page and running commentary with glossed vocabulary at the bottom. I would personally suggest buying the physical edition of Ad Alpes while just finding a pdf of Puer Romanus . All of these resources are intermediate level, so you can refrain from getting them until you finish Familia Romana .
Allen and Greenough New Latin Grammar is often used as the definitive sources for all things Classical Latin grammar. It is an extremely valuable
reference resource but is not written to teach you the grammar, though you can use it that way (my second and third year of Latin essentially boiled down to
studying out of A&G since I was studing for the NJCL grammar test).
Cassell's Latin Dictionary is an extremely useful dictionary to have more so for the English to Latin section than the Latin to English section,
since it gives nice ideas for translating English words to Classical Latin.
Logeion is an extremely useful online dictionary, especially because it is actually a
compendium of dictionaries, allowing you to cross reference between several different dictionary entries on the same word. I mainly just use it for
the Lewis and Short entries, though, since those are the most insightful.
An important part of language learning is listening comprehension and pronunciation. Usually, you would listen to native speakers and try to understand what they are saying and also imitate their pronunciation. Unfortunately, as you may be aware, Latin doesn't have native speakers, so we have to use the next best thing: youtubers (no I'm not joking). The best Latin youtubers are ScorpioMartianus and Satura Lanx. There are also some Latin podcasts too, the most popular of which is Quomodo Dicitur.