Start fresh with a clean installation of Windows 10

I've an older HP laptop which is running windows 10 home 2016 which was a windows 7 update at the time and I don't have the original Windows discs (lost) and it seems to have a separate partition as far as I can see but very little in it.
I want to reformat the unit but not lose windows obviously. What options do I have please
I'm thinking Start fresh with a clean installation of Windows 10 tool but not being a techno will this just swop windows 10 out and install a new and later 10 for me. I don't want or need any other files or programs that I can see.
Back up windows 7 is on the unit to reinstall but I can't see where it would be stored. I've seen create a recovery disk or image but would that include windows.
Is there anything else I would or could do.
Great for any help in a language I can understand lol and thank you.

Old laptop, you need to assess what is worth throwing at it, I reckon.

But- if you don’t need any of the programs on it- and the sums add up, I would:

Buy a new SSD (500gb) and a new 10 installation disc.

Start afresh with a clean registry and add what progs you need etc

Shame to shell out on a new Win 10 install for your HDD to collapse within a short time?

It's only going to be used for cycle training apps so was hoping to reformatting keeping the current windows as don't want to invest in it at all but not sure how to clean it and not lose windows. I have a piggyback HDD that I can use.
For instance if I reset the PC how will it reinstall windows if there seems to be no built in partition and I don't have the original discs?

AFAIK,

if you do the win7 to win 10 upgrade, it saves all your old stuff, and installs around all your stuff

Rather than the over the top start from scratch version

If you're currently running Windows 10 then look at this article: https://www.howtogeek.com/265054/how-to-easily-reinstall-windows-10-without-the-bloatware/ If you'r on a very old version of Win10 then let it update to the latest version first.
Alternatively, you can downloas Win10 install media from https://www.microsoft.com/en-us/software-download/windows10 You'll need an 8GB or bigger USB stick on which you create the install media.

Excellent thankyou