Learning declension endings
I like to learn the declension endings before I continue the course, but if I Google I get overwhelmed with new information and terminology.
Are there recommended resources that people have used to learn them? And is the best way to learn them 'with brute force' or are there widely accepted mnemonics?
(Latin teacher here)
I would keep a copy of the first, second, and third declension nearby. Glance at it when you aren't sure. Ignore the fourth and fifth until you're comfortable with the others.
The answer is LLPSI, Lingua Latina per se Illustrata (Familia Romana Pars I)
Brute force is how I learned them at school. I just chanted them repeatedly until they were committed to memory. Bear in mind that you will find different orders of the cases e.g. in the UK the accusative comes after the nominative, but in the US the genitive comes after the nominative. Pick one order and stick to it when learning the declensions.
The Cambridge Latin Course is accessible online: https://www.clc.cambridgescp.com/books/book-i. It's not perfect (for instance it introduces some cases rather late) but it's decent. I started learning Latin with this course and used to teach with it. However, supplementing it with other sources is key.
what i would do is what i did: working my way through "lingua latina per se illustra: pars 1 - familia romana".
For each declension class you will learn one paradigm noun. Focus on regular patterns and declension classes 1, 2, 3 first. This Memrise course with audio will help you if you take the brute force approach: https://www.memrise.com/course/1474021/latin-declension-nouns-audio/
Also keep a reference table nearby. Nothing beats tables...
FWIW, I memorized the paradigms (models of typical declensions and conjugations) by working through a primer and memorizing each new variety as it was introduced. I'd say each paradigm (to myself or aloud) until I knew it well, then wrote it down 10 times, longhand, then reviewed every day, then every few days until I knew them all. Here is a suggestion for writing each down 200 times! That seems rather extreme, but you can't argue with success, and his Latin is very good.
[Added] If you want to go the memorizing route, you could use the paradigm charts at the back of a Latin primer, or in a Latin grammar, or on a site such as bsun95 suggests, and each time you encounter what seems to be a new variety of noun, pronoun, etc., memorize the paradigm for it, which would space out the memorization somewhat, as it's rather boring to do a large amount of it at once..