Hi Melanie and welcome! And congratulations on your newly-wed-ness!
October is such a fun tie to go, what with all the Halloween decorations up. It's very festive
I agree with the others - I don't think I would bother with park hopper passes for a short trip, and would focus on just the 2 parks you are most interested in. You would lose alot of time with transportation.
A few things to keep in mind as you plan your park days.....
Mickey's Not So Scary Halloween Party (MNSSHP) takes place at Magic Kingdom on select days all through October (it actually begins in September). It requires special event tickets over and above your standard park tickets.
If you don't want to go to that event and don't buy the special event tickets, be aware that you will be gracefully kicked out of the Magic Kingdom park at 7:00 pm, and it will only be open after 7:00 pm to those that bought the special event tickets.
While Disney has not released the actual dates of the MNSSHP yet, the posted park hours for Magic Kingdom on Friday, 10/4 are 9:00 am - 7:00 pm. So it's a good guess that MNSSHP will occur that evening.
Therefore, if you don't plan on spending the additional money (about $60 per person) for MNSSHP, and you aren't getting park hopper tickets, you might want to consider doing Magic Kingdom on Saturday, 10/5, and do Hollywood Studios on Friday, 10/4.
Probably better anyhow, as the posted hours for HS on Friday 10/4 are 9:00 am - 8:00 pm (and extra magic hours starting at 8:00 am!), whereas they are only 9:00 am - 6:00 pm (with no extra magic hours) on Saturday.
Hope that helps!