Over at First Things there is a piece by Joseph Epstein about his decision, later in life, to learn Latin. It’s engaging. Read it there.
However, he mentions some sources for learning Latin, which I will countersign. For example, when people ask for a book for self-instruction, I usually mention Wheelock.
It is tried and true, available, with good ancillary materials.
And to go deeper…
Reginald Foster’s Ossa Latinitatis Solas
BTW… the 2nd Volume of Foster’s work is due to come out in August 2020. Ossium Carnes Multae e Marci Tullii Ciceronis epistulis: The Bones’ Meats Abundant from the epistles of Marcus Tullius Cicero