Can someone explain Doctor who?

Ok, so I finally decided I need to watch Doctor Who. I watched the first episdoe of season 1 and I was bored. So I decided to watch the first episode to season 6 so far its awesome. but I’m so confused. I thought the doctor was dead? Now he’s not? and whats with “the space man”? And ugh where should I start, I heard the first season sucks, but the 6th season is awesome. So where should I start the series, where I won’t be beyond confused, and I won’t be bored?