Moggie. At first, I'd be inclined to warn you off going with a Chromebook as it will definitely be different from what you are using. OTOH, the circumstances of why you have this choice may be sufficiently strong to justify using the Chromebook. For example, it may be an unwanted gift that someone has and is happy to give to you.
There are quite a lot of different Chromebooks on the market, so it would be easier for people here to advise you if you could give details of the make and model.
Another major consideration to take into account is what you use your existing computer for and what software, if any, that you have bought or use, even occasionally. In particular, do you use things like Word, Excel or Powerpoint? How do you access your email? This might be simply by going to Gmail or Hotmail by using Web access or you might use an email client like Thunderbird or the built-in Mail client.
Do you have access to anyone technical who could help you with transferring data from one machine to another? (This is something that you'll have to face at sometime or another, whatever your choice at the moment.)
Lastly, it would be helpful to know a little bit about your existing machine. Roughly how old is it? Do you know which version of Windows it uses? (e.g. XP, Vista, Windows 7, 8 or 10.)
It's quite a lot of questions, I know, but without knowing these sorsts of details, it's hard to give sensible advice.