Hi there... I also recently started a tank about a month ago. So far I think the most important thing I've learned is to do your own research before you buy something whether it is a piece of equipment or living creature for your tank. I say this because there is a conflicting opinion for almost litterally everything. There are 4 LFSs in my area, and they would all give me different answers to the advise I was looking for... and their answers might conflict with advise you find here. In my experience when you go to a store, if you wind up chatting with the manager/owner, they seem very geared towards making the sale... but if you happen to be talking to the kid who's there part time for the summer, his advise is more honest. For example, When I told one guy my tank is only a month old, one store manager said I could start adding some starfish if I wanted too lol... and that they just happend to be having a special on stars lol.
Regarding the Damsels, I've heard that the Dominoes are the most aggressive out of all the starter Damsels. When it was time to add my 1st live stock, I went with an Electric Blue Damsel and a Yellow Tail Damsel. Both fish seemed happy and were eating immediately after being acclimated. However, the Blue Damsel became such a bully! If the Yellow Tail so much as left the back corner of the tank the Blue would attack him. After about a week I took took the Blue out and replaced him with a Blue/Green Chromis. Ever since then the Yellow Tail has been happy and has gotten along great with his other tankmates. So, if you're going to go the Damsel route, I'd recommend a Blue/Green Chromis and a Yellow Tail Damsel.