There are literally thousands of sites that will give you free stuff to help you play. Below are a few of my favorites.
dndadventuresforkids.com – A site dedicated to creating and distributing free D&D adventures for kids.
Fast Character – Need a character really fast? It doesn’t get much faster than this.
DnD Lounge – From backstory generators to spell guides, dndlounge.com makes filling out your character faster and easier. Matt Zane delves into the arcane and demystifies some of the more complicated aspects of Dungeons & Dragons.
Dungeon Masters Vault (formerly OrcPup) – This is a very easy to use site that allows you to create, download, print and share characters and other D&D 5e content.
Dyson’s Dodecahedron – Dyson’s blog has some of the best maps. He has a lot of free content you can download and he takes commissions if you need something specific. Consider supporting Dyson on Patreon.
5emagic.shop – Need a quick magic items shop for your adventure? You are just seconds away with this site.
Donjon – Need a quick random dungeon generator? It doesn’t get faster or easier than this. This generator creates old-school dungeons, which are great for dungeon crawls.
dndbeyond.com – D&D Beyond is a web app that lets players create and store characters, peruse items and monsters and consult digital D&D tomes, among other things. It’s a “digital tool set” for the game. Accessing premium content does cost extra. In some cases, it is cheaper to buy the books online.
dmsguild.com – The DM’s Guild is an online resource for free and low cost gaming materials, modules, adventures, digital books, maps, and much more.
tools.goblinist.com – Need a quick random encounter? It doesn’t get much easier or faster than this.
Nerdarchy – For Nerds By Nerds. Tabletop RPG Enthusiast with a particular soft spot for Dungeons and Dragons.
The best simple map maker for D&D: Donjon
The best city map maker for D&D: Medieval Fantasy City Generator
The best D&D map maker for creating continents: Wonderdraft
The best D&D map maker for generating whole worlds: Inkarnate
The best battle map maker for D&D: Wonderdraft
The best 3D AI map maker for D&D: Dungeon Alchemist
The best old-school map maker for D&D: Dungeon Scrawl
The best free virtual tabletop map maker for D&D: Roll20
The best customisable map maker for D&D (that’s also open-source): MapTool
The best premium virtual tabletop map maker for D&D: Foundry Virtual Tabletop