Getting Started with Self-Study*
*A very basic guide for my nephew and any others wondering where to start.
For Very Beginners
In the beginning it is good to focus on lots of listening to train your ears to hear the sounds. If you can't first hear the sounds, you won't be able to pronounce them correctly. Focus on the sound by listening a few times without subtitles. Reading is great for building vocabulary, but your English knowledge may interfere at first. Your brain will tend to distort the Spanish sounds as it tries to fit them into an English schema, since English and Spanish use the same alphabet for slightly different sounds.
Peekaboo, I Love You
Do you Like Lasagna Milkshakes?
These are books in both Spanish and English. There is debate around the value of these books. It is probably more efficient to read or watch material that is at your level and work out the meaning from context, but some learners have a low tolerance for ambiguity. Learners with a high tolerance for ambiguity are able to enjoy immersing themselves in a story without needing to understand 100% of the words. If you have a low tolerance for ambiguity and get frustrated or bored by Spanish-only content, you may want to try some of these. (Bilingual books are also useful for less popular languages were content at your level is hard to find.)
Preciosa / Lovely
The First Well
Note: Bookbox has a mobile app if you are concerned about your child getting distracted on Youtube.
I Want My Hat Back
The Next Step
Once you get a little further along a Netflix or Disney+ subscription is very useful so that you can immerse yourself in enjoyable content for hours at a time. If you are watching more difficult content that requires English subtitles, I highly recommend watching the show at least twice, leaving the English subtitles off the second and third time.
Reading: Leveled or graded readers are very easy to find in both English and Spanish. StoryWeaver has a free collection of children's stories. Amazon has a huge selection of Spanish ebooks. Also, LingQ is well worth the money at this stage too (~$15 / month).
Speaking & Writing: This is where classes and travel really come in handy, since it is much harder to do on your own. However, a solid foundation of listening and reading skills will greatly accelerate the process once you do get a chance to practice speaking and writing. There are lots of apps for finding language exchange partners, such as HelloTalk and Tandem. However, be aware of users who treat these as dating apps. If you want to pay a tutor to speak with you, check out iTalki.