Trying for baby #2

My daughter just had her first birthday this last week and my mind keeps wondering to having another baby. I'm 20 and my fiance is 21, hes got a good job, and we are at a great place in our relationship. I get so excited at the thought of having another but then I think about being pregnant and having a newborn all over again, but this time with a toddler. I was sick with my first the whole pregnancy so I'm also really nervous about that. any advice? What are the age gaps between your kids and what was it like?