i'm darknetmatrix on the web, user of Solus and OpenSuse tumbleweed & windows 10
Just downloaded the 2020.07 ISO.
I want to install this dualboot on my existing windows 10.
Are there any guidelines I should follow?

General Install Guide is included in the ISO (Welcome App). I presume this will be an UEFI system, then Windows will be automatically added to the systemd-bootloader menu.