Drew Neil's awesome vimcasts¹ are available, while no longer getting updates they'll still be pretty useful. Also a /big/ fan of his Modern Vim book², even after literal years of vim use I still found a bunch of new-to-me information inside it.

¹ http://vimcasts.org/episodes

² http://vimcasts.org/blog/2018/05/modern-vim-now-shipping/