Welcome to the Hubitat community!
I think this is something you have to think about your house and household habits a bit, and decide how to solve that problem.
For me, I started out with some simple stuff like "wouldn't it be nice if the outdoor lights came on when I open the garage door at night?", or "it would be cool if the bathroom fan came on when the humidity gets too high from the shower and turned off when the humidity returned to normal.". Things like living room lights turning on at dusk or bathroom lights coming on very dim in the middle of the night via motion are common things people start out automating.
There are lots of examples of this on this and other home automation forums like Reddit if you need inspiration, but it might take some digging and reading or some specific google searches to find lots of unique samples of what people have done.
As far as devices, the nice thing is a hub can use various brands and protocols to create these automations. One place to look for what devices is the compatibility list, which is all the confirmed nice players with Hubitat. List of Compatible Devices | Hubitat Documentation
There are certainly other devices that work with Hubitat beyond the official list, this forum is a good place to search, but you may need to have some specific things in mind when searching, an example would be you may want to search for something like "Z-wave dimmer". Beyond a basic search, there are some fairly recent "best of" lists compiled by users that may help. Most Popular Motion Sensors in 2023
The other thing I would say is to post here with questions, you will typically get some good feedback if you post and say "how do I make my lights come on at dusk" or "what light switch would you recommend given that I want XYZ". There is a bit of a learning curve with any device like this, and users here are willing to help you, were were all in your situation at one time.
