Lessons
Sanskrit
Bhaskara Prakasha Ashram has a YouTube playlist of Sanskrit lessons.
Sanskrit.Today has a Sanskrit for Beginners playlist. This channel also has videos of Sanskrit Grammar.
The Sanskrit Channel has periodic live lessons.
Yes Vedanta has a very good Sanskrit for Beginners Course. Check the site for registration.
The Joy of Sanskrit class from Australia National University also has the syllabus and lessons online.
Bhagavad Gita
Devi Mahatmyam
Bhaskara Prakasha Ashram has a playlist from 2020 classes and current lessons. The text is available too.
Sri Lalitha Saharanamam
Classes and practice sessions presented by Bhaskara Prakasha Ashram.