I'll echo this, go for whatever of the 3 suggested brands your local music shop sells, standard nickel plated (unless you have a nickel allergy in which case go for stainless steel)
there are youtube tutorials showing you how to change strings or if you've got a guitar playing friend then buy them some biscuits or a beverage of their choice and get them to show you how to change them.
if the guitar is new then the strings will be ok for a while yet, give them a wipe down with a clean cloth after each time you finish playing and they'll last longer before they need replacing.
In a year or so you might decide you want to change the gauge but until then your main focus should be learning the guitar.
Matt