If you are looking for a free alternative to Dnd Beyond then I recommend Dungeon Masters Vault: https://www.dungeonmastersvault.com/
They don't have an integration with Roll20 like you can get with DNDB but it works excellently for most other use-cases - if you're looking to use non SRD content you'll need to download the relevant expansion files from this spreadsheet and import them:
(sourced from Reddit here: https://www.reddit.com/r/dungeonmastersvault/comments/qa7eqw/all_content_orcbrew_file/)
You can drink the tap water in most places in Iceland without boiling it (especially in Reykjavik), but if you're further into the countryside then I would check first!