why is there a + in front of my phone number?

+ in a phone number represents whatever dialing code you need to invoke international direct dialing.

This is followed by the country code, and then phone number, usually dropping what ever code distinguishes national from local numbers. My number in the UK is 020 7... which becomes +44 20 7...

tt2

In North America, the phone number of the form 1-areacode-number is interpreted as:
1 - North America (and some of the island territories, I believe)
areacode - your general geographic area
number - you phone number

Somebody calling you from overseas has to dial a code before the '1' to call you. With a mobile phone, they can simply dial a +. '+' is used to indicate that you must dial the international access code.

For example, somebody calling you from the UK would dial 00-1-areacode-number. From South Africa they would dial 09-1-areacode-number. You would publish your number as +1-areacode-number.

Generally, from a cellphone you can simply dial + before the country code.

iinami wrote:
...no country code.

The country code for the USA is 1.