I am sorry to say it is clear you do not fully understand things. Kyhi's explanation assumes some basic knowledge of windows and is pitched at the right level.
If you do not have the basic understanding, this tool is far too powerful for a beginner and you will probably break more things than you fix. You would not give a petrol driver chainsaw designed to chop trees down to a young person starting his first job would you?
I know you mean well, but to comment on your specific points
1) Download that magnificent program, the one with 64x (that is for us, the normal pc-users)
It depends if pc is 64 bit capable - devices older than five years may not be, and you would need 32 bit version.
2) Format the harddrive/USB in Fat32.
Format drives by using diskpart commands by going to a command prompt from any modern windows install disk. You can easily create a windows 10 install disk using windows 10 media creation tool
Select the quick option i.e. "format fs=fat32 quick" and it takes less than 10 seconds.
Also see comment 4 re. Rufus.
3) When you put your broke pc on, push F8 to open the Bios, ENABLE SecureBoot and make sure itís on UEFI.
Depends if pc is uefi compatible - older systems may only be legacy bios capable.
4) How to put the WinPESE_x64 20160125 on your stick?
Kyhi's way is the traditional way that does not require use of third party tools and is fine but may be a little daunting to beginners but is easy to do if you follow his instructions.
Others prefer to use a tool like rufus - many guides on web. With rufus, you do not even need to format the drive - it does it all for you.
that is a windows function - nothing to do with iso.