Welcome to :AA:! There are lots of helpful voices around here, who will help on re-stocking. Nice to hear you are concerned about the maintenance too.
I have to say that some LFS
do "lie" or bend truths in order to sell you fish and products, however some shops can be very helpful and knowledgable, you just have to find the right one first.
The best way is to research your fish before you go looking, so you know what kind of fish you are looking for and don't get side tracked with fish too large for your tank. Most people have a look at the fish and decide on a pretty fish with no idea on its correct tank size and tank mates or water conditions, so research research research before you go shopping.
Did you clean out the whole tank? I assume given its been neglected it's cycled but just needs proper care to get it up to standard for fish?