Some random thoughts about having two kids.....I think it is very normal to wonder how it's possible to love another child as much as you love your first (that love that turned your world upside down and you had no idea it could be so strong, until you met your baby for the first time). But then you do love your second just as much, your heart just opens up. I still miss our little threesome, I treasure those days. But four in our family is wonderful too. I like watching the kids interact, I like it that now there's more love to go around for everyone. I love seeing how my dd is different from her brother, and how she is the same. I like seeing these two little people becoming themselves.
One thing I have a hard time with sometimes....I feel like at any given moment I do enjoy the developmental stage of one kid more than the other, and I try hard not to let that translate into favoring one child over the other. For example, I really love the 6-15 month stage, I find kids that age completely adorable (and much easier that 4-4.5 year olds, which was my ds's age at the time). But now dd is at a stage where she tantrums a lot and can't express herself verbally very well, leading to constant frustration (from her and me), and ds is at a stage where he's more fun to be with. So the roles reverse often, and I try to accept that I love them both equally but sometimes I like one child's behavior a little better on a given day.
Anyway....it's an adventure. You'll do great!