TRADITIONAL ANIMATION DISCORD
This is a very friendly Discord server where you can get feedback and support no just for animation but for things like character design, background art and storyboarding as well.
Use this invite to get in and be part of a great community!
A really nifty free program that lets you drag and drop images to use for reference.
Combined with pinterest you can make custom mood/reference boards really fast and easy.
*Tip: set your boards to embed images, this will make for bigger file sizes but will save you the heartache of opening an older board that you want use only to find most of the images are missing.
This program isn’t free but well worth the price imo.
Originally it was just a tool for getting smoother lines in Photoshop as it didn’t have line stabilizing at the time (does it have it now?) but the brilliant dev Guillaume added many features over time making it super usefull for users of all art apps.
The rulers are particularly useful for drawing mechanical things and backgrounds.
THE STRING BING WORKSHOP
This course certainly isn’t free but compared to other animation courses it’s a great deal!
Toniko Pantoja is hands down the best animation teacher online imo. The way he explains all the fundamentals is simple and clear and the exercises in this course will get you up and running with traditional animation.
If this is out of your budget – and it might well be, I’ve been there – then you should check out his youtube channel which full of great tips and advice.