Newbie - just a coupla questions

Hi,
I just found home assistant and I am just wondering if I will be able to use it to do what I’m hoping to do.
I have read this great thread… New to this, project for me and a 9 year old
and thats answered a lot of my initial questions… but please forgive a little impatience and just a desire to know if I am on the right track before going too far…

Right now all I want to do is monitor the temperature in the rooms in my house and compare those temperatures over time.
Maybe on a chart…
I’d like to see when the heating goes off and how fast the rooms are cooling down after that.
I’m embarking on a retrofit insulation project next year so i’d love to be able to compare before and after charts just to see how much things have improved…

So I’m wondering what sensors I can buy to use for this?

Can they be battery powered? (have small kids with busy hands so want to tuck them away if possible)

Also I have an older Pi 3… not sure exactly which model. Wondering if a Pi zero could be used?
Or is it underpowered…
I also have a small older HTPC running windows 7 that I could use for this… but is the only way to run on a PC to use a VM ?

Thanks

A Pi3 is okay but nothing less than that
Look at the Need Help ? / Getting Started Page to see recommended platforms.
A Windows PC is definately not the way to go, Random Reboots and upgrages cause havoc
There is a thread (search for it) on temperature / humidity sensors, there’s a lot of information in there