Media Creation tool on a stick, what now?

My laptop has not been on for about 2 weeks, or only in the troubleshooting. Now I have the Media Creation tool with the help of a buddy on a stick, but now I do not know how to start it.

The Media Creation tool creates a bootable USB stick.

Did you now pull the tool on your USB stick or did you already run it on your friend's computer and all of the data needed is installed on your USB?

Also, if your USB flash drive is now bootable, you must first plug it in before starting the laptop. Then, while your laptop is booting, press a key combination to access the BIOS menu. The key combination varies from manufacturer to manufacturer. Then, once you're in the menu, you'll need to change the boot order. That is, your laptop should not start from the hard drive, but from your USB stick.

Hope I could help

From the discussion so far arises for me the question:
What would you like to achieve as a goal?

If you want to install Windows 10 on the (as you say) aged, slow laptop, you should first check if that works too!

When Win10 was introduced, there were a lot of tools to check it out, I picked this page out:

https://www.giga.de/...ft-ihr-es/

What keyboard shortcut does Lenovo have?

I just googled for you: you have to press after the start immediately on the F12 key. Important: keep pressed

Not the same for every Lenovo device: https://tipps.computerbild.de/hardware/firmware/lenovo-bios-taste-so-kommen-sie-ins-bios-325349.html