Welcome!
can data be shared between so when I travel I have everything ?
In general, yes... but with a possible "maybe." When I had to work on files from both Mac and Windows computers, I put the files in DropBox, but iCloud Drive is just as good. I had no issues. However I was only working with Excel and Word files.
However, if you have files created on a Win app that does not exist for Macs, that is a big problem. Example: MicroSoft has not issued a Mac version of Access since before OSX launched 23 years ago. LibreOffice has a component that supposedly is Access-compatible but I have not used it.
If you post the apps whose files need to be shared, perhaps we can give more directed help.
Also, if you have a WIn license for an app, you have to buy another for the Mac unless the app developers have been overcome with a massive sense of benevolence
If you are asking if you can use the iMac as a larger monitor for the Win notebook, then no. Target Display Mode has been dead for over three years and never supported non-Apple devices when it was a going concern.