Welcome to FT. Great to have another Loiner onboard.
I have been in the LBA lounge a few times now when on BA. You should get to go through the fast track security lane. There are two parts to the lounge, one either side of reception. To the left is a more business friendly part, and to the right is a more leisure family friendly part. The leisure part is a lot larger, but can be filled with families.
If you want to get wi-fi a code is needed but it is displayed around the lounge. When I was there the offering included soft drinks, coffee, tea, beers, and a small selection of wine and spirits. There are usually some nibbles of some sort on offer as well.
Some photos of the lounge for you:

One half of the business part of the lounge with door back to reception on right, and drinks & food to left.

Views from the other side of the drinks/food island.