Help with updating Windows 8 to Windows 10?

I have installed Windows 8 on my laptop. But I would like to have Windows 10. How do I best proceed or where can I find the cheapest Windows 10 update? And how expensive is it approx?

You can do that for free. Enter Windows 8 on Windows 10 in your search engine and download the tool from Microsoft or e.g. Chip, start the program and follow the instructions.

Updates never cost anything. All you have to do is pay for the "premium variant".

Visit the Microsoft website and download the https://www.microsoft.com/.../windows10
Use the tool to create a bootable USB stick with Windows 10
Boot from the created USB stick and install Windows 10

And how expensive is it approx?

As the owner of a Windows 7, 8 or 8.1 license, the upgrade to Windows 10 is free for you. Officially, the free upgrade was only offered for a limited time, but it still works to date. So there are no costs for you if you update to Windows 10 now.

If something should be unclear or if there are further questions, just ask again. I will be happy to help you if necessary.

This is not about an update, but an upgrade. This can cost money, regardless of the version. But yes, the upgrade to Windows 10 is still available for free.