My phone is not letting me make calls or go online

My phone is not acting right. Whenever I call anybody, the person I try talking to cannot hear me at all, they're saying "hello? Hello?", and I'm saying "can you hear me? Can't you hear me?", but they can't, they just keep saying "hello?", and then hang up. And now, most of the time I try to go onto the internet, it won't let me having the little box pop up saying "we can't connect you". I was thinking that I need a new phone with the me not being able to be heard while making calls part, but what about me not being able to get online about 80% of the time I try to, is that me needing a new phone too?