[Edit] I haven’t used D&D Beyond yet, seems expensive. I haven’t bought any of the fanmade material from the DM Gulld yet, but I have made use of an earlier version of it when it was a more obvious corner of drivethrurpg.com. That was and is a good way to get pdfs of hard to find modules, or even Print On Demand in some cases.
I’ve kind of been thinking about becoming a patreon of The Angry GM/DM once my finances allow for more discretionary funds to be disbursed. Behind his shtick is a wealth of good ideas.