EUR/USD is the most traded currency pair on the Forex market with a very tight spread. All the newbies are advised to start their trading career by starting their trades on this currency pair. Moreover, you can trade on any currency pair which you feel is the best suitable for you.
I don't think that EUR/USD is necessarily the best pair for a newbie. Yes, it is very popular, but on the other hand it often moves in a choppy manner and is prone to being range-bound.