Stash buster

[Ellen garrett]

I don’t understand the letters and numbers put with the crochetalongs.

Can someone explain it to me

[Granny Square]

Hi Ellen, welcome to the 'ville!

The best place to ask would be in the crochet-along section, this 'help area' is for "I don't understand what XYZ pattern line means, can you help me interpret it?", or "I want to make something like the item in this photo, what stitch is that?" sort of thing. 

Here is a link to the 'first page' of the crochet-along section, I think this answers your question, it looks like the group has made it into a sort of game, this explains the point system.  Link, to the first page.