A third person has access to an old apple device of mine and I suspect it's being used to spy on me, help

I had to get out of a difficult situation and left my ipad behind, with my appleid logged in. I strongly suspects this person is using it to spy on me, via findmyiphone and my photo gallery (since I have enough storage on my icloud). I changed my appleid's password today and logged in on my phone. What will happen to the ipad? will it be unusable? will it be usable but will no longer be updated with things from my icloud?

Any other suggestions?