I'd highly recommend signing up for an account with Inkarnate.com to be able to browse the gallery. You can go with a free account and then be able to download a HUGE selection of maps that exist there. You can eve then use their free tier to dabble in map creation. Plus their Discord community is amazing!
As someone who creates maps myself for my campaigns though, I've got to say that I know how long it takes to create a good map...hours. Even then most of mine are pretty mediocre. The really good maps people create do have a value, and if you possibly can it's far better to support a small creator or fellow DM with a $1 or two. I hate suggesting it because their cut is indefensibly high, but DriveThruRPG has loads of packs for only a few dollars here and there. At least that way creators get something for their efforts.
If you can't there's loads of map making tools out there that you can quickly use to knock out a basic battlemap though.
Does DDB have any free battle maps?
DMing:
Dragons of Stormwreck Isle
Playing:
None sadly.
Optimization Guides:
Literally Too Angry to Die - A Guide to Optimizing a Barbarian
Free no. On the Internet, yes. Just do a search in your favorite search engine, and you should be able to find some.
I'd highly recommend signing up for an account with Inkarnate.com to be able to browse the gallery. You can go with a free account and then be able to download a HUGE selection of maps that exist there. You can eve then use their free tier to dabble in map creation. Plus their Discord community is amazing!
There's a fine selection of maps over at Free Map Library - RPG maps for Roll20 and Tabletop — Dice Grimorium
As someone who creates maps myself for my campaigns though, I've got to say that I know how long it takes to create a good map...hours. Even then most of mine are pretty mediocre. The really good maps people create do have a value, and if you possibly can it's far better to support a small creator or fellow DM with a $1 or two. I hate suggesting it because their cut is indefensibly high, but DriveThruRPG has loads of packs for only a few dollars here and there. At least that way creators get something for their efforts.
If you can't there's loads of map making tools out there that you can quickly use to knock out a basic battlemap though.
DM session planning template - My version of maps for 'Lost Mine of Phandelver' - Send your party to The Circus - Other DM Resources - Maps, Tokens, Quests - 'Better' Player Character Injury Tables?
Actor, Writer, Director & Teacher by day - GM/DM in my off hours.
If you buy an adventure on DDB then you can download and print out the player maps.
I don't know if there are free adventures here which provide such maps.
Inkarnate. Super fun and easy to use. You can do simple battlemaps, detailed battlemaps and even whole towns, cities, regions and worlds.