number 1 item to get that you can use to segregate a space for them and grow as you get more room or get more trust in them.
https://www.amazon.com/dp/B09SZ896MR?psc=1&ref=ppx_yo2ov_dt_b_product_details
These panels are perfect for the type of people that can deal with ferrets. you start with one pack and build a little pen or like I did use it to build walls around where you don't wan't them to go. And then almost immediately they make you feel like an idiot and find a way through something so you get more. And grow it. And more. And grow it.. Until the ferrets get their own living room.
And then you use them to open up a walkway to your bedroom and close off access to the closet and side of bed...
Other things to add, like above posters said get a ball pit.. oooor.. something like this :
https://www.amazon.com/gp/product/B09B9QTFV4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I got a big bag of the balls and filled the main area of this with them, and then just because i noticed my little guys were psychotic and loved belly flop on top of it, i had a crazy idea.
i took one of these and some zip ties
https://www.amazon.com/gp/product/B07XL93FNW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
and fastened it so that the bottom of the cheaper one was on the top of the one with the tunnel, and all the supports were doubled up, and now they have a trampoline the belly flop onto, wrestle on, and act like maniacs with
https://www.youtube.com/watch?v=E6r_wlBnNmM
tunnels.. lots.. mix it up between the marshalls 15ft one and 4" wide clear dust collection hose. get a bunch of T and Y fittings and make a maze. with a bunch of exit points. they will love you for it.
https://www.amazon.com/gp/product/B0013EOTRW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B005VRJIW8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B09S9WTXY4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B0002DJL0K/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
get a storage container (not too too tall below is a decent height) and toss some yesterday's news style litter in it..
https://www.amazon.com/dp/B0B3S4KN6J?psc=1&ref=ppx_yo2ov_dt_b_product_details
annnd you get a dig pit for psycho ferrets to wrestle in
https://www.youtube.com/watch?v=0g9OgOt_ru0
cat towers are a good thing, but dont go too too tall or they'll just walk off because well.. ferretts.. those you can probably get at a local store more easily than amazon. good for routing tunnels over and around too. Just keep it clean cause they will rip up the carpeting .
and if you have any floor space left.. get a sphero.. or a nice super padded rc car https://www.amazon.com/dp/B084BMXHLH?psc=1&ref=ppx_yo2ov_dt_b_product_details
good luck. enjoy the extra space your ferrets will steal from you!
I ordered it from Amazon.
https://www.amazon.com/dp/B07XL93FNW?ref=ppx_pop_mob_ap_share