There are two set's I'd recommend highly:
"Immunity" by Alan Belcher.

It shows a lot of good escapes and defences to the common submissions. It's best to not get that far, but if you end up in a bad spot its good to know something to try and get out https://bjjsuperdeals.com/product/immunity-mma-grappling-5-dvd-set-by-alan-belcher/

And "the blue Belt requitrements"- by Roy dean

It's a great coverage of the basics. https://www.amazon.com/Brazilian-Jitsu-Blue-Belt-Requirements/dp/B001ADKATC

Hope that helps. Keep training