I am not sure if wordprocessors are still around, even if you managed to buy one, what would happen if and when you needed repairs/spares. I personally would buy another laptop if you are most comfortable with that.
I'm curious to know why you need a separate laptop for creative writing. Why can't you use your current one? There are plenty of 'word processing' apps you could download to your laptop. Just using a laptop to access the internet by carrying out a bit of web browsing is not using any of the capabilities of a modern computer. Do you want to keep your writing a secret perhaps or are you worried about security? You could easily create another user with a new password on your computer. Also it's very unlikely that a modern printer would work with an old fashioned word processor if you could get hold of one. If you could say why you can't/won't use your existing laptop for creative writing, perhaps other Gransnetters could suggest some solutions.
You could buy an external keyboard to use with your existing laptop. It would cost a lot less than a new laptop. Even adding a monitor to display your writing on screen and just using your laptop for storing your data would be a cheaper option. I suppose if you only use a laptop on your lap, it could be more difficult.
There are a few suggestions online. I Googled 'best laptops for writers' and there was some advice there although no mention of wearing out keyboards. Some of the gaming machines are necessarily built with better keyboards but they would be expensive as they contain specialist graphics cards. I guess you need to spend some time trying out different laptops/keyboards for comfort and wouldn't need an expensive or particularly fast laptop, just a mid-range workhorse. Good luck with it.