Hi there, welcome to the forums!
Congratulations on getting your budgies! They sound like little darlings and what adorable names!
You've already been given great advice and I can't add much more
Patience is really the key, after a few weeks my girl (also from a pet store) was still very skittish. Move slowly around them, like when you're cleaning their cage, and talk to them softly.
Also, budgies love music, so be sure to leave the radio or something else on while you're gone. In fact, silence means danger to budgies, because when the flock fell silent in the wild, it meant a predator was near.
I'm glad you're doing such thorough research and the relationship you have with your budgies will really reflect that.
I hope to see you around the forums and we'd love to meet Pudding and Spoon sometime!
If you have any questions after reading though the links Deborah has provided, feel free to ask!