There are many things to consider when starting out keeping fish. Why not start a thread in the beginners forum and ask this question. If you tell us a little more about the size of your tank, etc., we'll help you figure out if they would be good for you, or if there is perhaps something else that would work out better.
Also, if you put your age and location in your profile, it will help us give you more accurate information too.
Welcome to the forum!
Guppies are a very good beginner fish, beautiful colours, very peaceful, affordable, doesnt grow too big. The only downfall is they reproduce madly(30 or more babies a month per female) but if you only keep all males or all females then you have that problem fixed. Dont let your friend think negative of them when its something so minor.