if it is indeed a VdB, you scored. it takes several years to root and get a tree that size, with a proper pruning coming Feb or March, (check with your so. Cal fig people) so you do at the right time, you should have amazing fruits.
Remember, Brebas grow on last year's growth. So, if you ever prune a branch that is this year's growth, make sure you leave always a 2 or 3 node, so that next year a growth on this year stub will fruit for you.
I have 3 VdB from various sources, and their fruit all appear to be a bit different. My first breba, almost black was super delicious.