Is it cheaper to buy Orlando park tickets before we leave home or in Orlando. Thank you?

depends on where you live, what parks you want to go to, and how many days.

if you want to go to universal orlando and seaworld if you buy multi day tickets online you'll get a discount.

if you want to go to disney world the price is the same at the gate as it is online unless you're from the UK then generally prices are better online because they give a better discount for people coming across the pond.

you'd also get a good discount if you area florida resident or a member of the us military.

They are exactly the same price. Disney and Universal control

all ticket prices and they will never be different one place or another. Buying on line of course you will avoid the lines to buy tickets at the parks.

It doesn't really matter. But avoid the TimeShare "deals" - it's a sales ploy, and pressure you don't want or need. Don't buy into fake pages that claim you can get free tickets and such because that just doesn't happen.