Dual linux install, noob question

Hi there
On my Victus laptop, which has already Manjaro installed, for the second ssd (newly installed, unformated and from different brand), I would like to install a second Linux on it. Are there some tips or warms to know?

Thanks

Os prober is disabled by default so you’ll probably need to enable it. Also some distros grubs are strange
I know manjaro grub can boot mint but mint can’t boot manjaro so that’s something to be mindful of.
As long as you have a live USB of manjaro you’ll be able to fix any potential issues

Thanks a lot for your return ,could the best way is to disconnect Manjaro disk? I can always use the bios boot menu, maybe this way should be the safer way, no?

No, just do as suggested enable OS Prober in both Manjaro and your other OS, install you other OS, you may have to go into your bios once to set Manjaro as your default if your new OS doesn’t pickup Manjaro. Manjaro should pick up whatever other OS you have installed as long as you enable OS Prober and manually update grub.