Having had first hand experience of a rescue kitten I can assure you that the best thing to do when you first get home is leave the cat in it's travel cage and put it somewhere quiet. After about 30 minutes put some wet food near the travel cage, a few feet away and open the door then leave it.
Your new friend needs to settle down for maybe a day or two. Put the litter tray in sight but not near the food if you have a spare room you could leave the kitty in there until it's settled, you'll know when because it will want to explore, now start talking to it so it'll learn your voice.
Let it come to you in it's own time don't try to encourage it.
Sisal rope is what you'll need if you're going to build something for scratching purposes, can also be used for climbing. The best place for ideal is online pet store who sell climbing frames.
Cat have very good sense of smell not as a dog but they can put off by the way something smells so don't use any glue in your builds.
Catnip can be calming, stimulating or have no affect at all but usually just provides pleasure.
I know this isn't what you asked but I just thought I'd share what I learned from my Toby.
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