Hi Jason,
So happy to know that you are enjoying being back to #100DaysOfCode 
I absolutely am… I myself touching Android Development after almost a gap of 2 years… 
Its a tough ride but small steps make a difference 
I am a self-taught developer, with the help of the community of course 
and it makes a lot of difference when you are working together… 
Please feel free to give a shout if you feel stuck on a concept, we have lot of MongoDB folks to jump and help 
and @Kushagra_Kesav is one of our champ 
For Javascript, I recently got email from FreeCodeCamp, to learn Javascript while making games… I have not explored it much yet but I hope it provides some help 
Keep Rocking 
Cheers 