The word "ideally" means "in the best situation". "Ideally" introduces something that you want, but don't feel confident directly stating because it's difficult or unlikely.

For example, if someone asks you what you're going to do after you graduate college, you can say:

Ideally, I'd like to get a job at a technology company in the U.S.

Getting a job in another country is hard, so you feel like it might not work out. That's what "ideally" suggests.