My initial thoughts: when going first, you have no choice but to open the board, but you get to choose how you want the board to be opened, most likely based on your rack and if you know your opponent's playstyle. When going second, you can choose to either open the board more or close it, but you have less control over how the initial board is opened.
I feel like I might be missing more than just those differences though.
There's no real difference other than, if you go first, you get an advantage worth roughly 10 points (because you are starting on a double word score tile, and if you can make a 5-letter word, also a double letter score tile).
Only thing worth noting if you go first is not to give up easy double crosses on the double letter score tiles near the starting tile. For example, if your starting word is FAME, you should not play it such that the two vowels are next to the double letter score tiles.
