Below are tools I’ve used personally and found useful. Please visit this page periodically for updates to the list.
For language learning
Dictionaries, translators as recommended by the Spanish subreddt.
Ana, the energetic and often funny Mexican Youtuber will entertain and teach you Spanish in her Butterfly Spanish channel.
For cultural immersion
If you are going to read only 1 book, make it The Story of Spanish. This is not a grammar book… it is a story book about the language. Informative, yet easy-to-read and interesting. Highly recommended.