It is recommended to change the factory installed set of strings once you get your guitar... you won't know how long the guitar has been on the shelf and how many people has played with it before.. FYI, wound acoustic bronze strings have very short lifespan... they lose their brightness in about a month

You can give GHS Bright Bronze a try... They are bright enough to last you a couple of months on tone... As for the string gauges, don't differ from the factory ones by a lot, as this will cause intonation problems... You can just ask for regular gauge at the shop...

It's around 24 bucks a set... not sure about single strings though...

Remember that guitars do spend long periods in warehouses, cargo ships, planes, etc.. before settling down in a music shop somewhere in the world

Always use light picks for picking and strumming on the acoustic... they sound the best as you get the scratch and attack from the lighter picks... never use heavy picks