Mojave MacOS: Dual boot and refind boot manager

I plan to dual boot my MacBook Pro 2018 (10.14.3) with ubuntu 18.04.02

Τhe relevant guides one can find by googling a bit suggest to have refind boot manager installed.

When I try to download and install it, I get:

./refind-install
Not running as root; attempting to elevate privileges via sudo....
ShimSource is none
Installing rEFInd on OS X....
Installing rEFInd to the partition mounted at /Volumes/ESP
Found rEFInd installation in /Volumes/ESP/EFI/refind; upgrading it.

**** ALERT: SIP ENABLED! ****

You are attempting to upgrade an existing installation, but it appears that
System Integrity Protection (SIP) is enabled. If rEFInd is working now, then
this is fine; you can upgrade your existing rEFInd. If rEFInd is not working,
though, re-installing from this boot will not help. To re-enable rEFInd, you
must re-install it from a Recovery system or from another OS. To enter the
Recovery system and re-install rEFInd:

  1. Reboot
  2. Hold down Command+R as the chime sounds
  3. When the OS has booted, select Utilities->Terminal
  4. Change to this directory with the 'cd' command; it will probably be under
     /Volumes/Macintosh HD/Users/pkaramol/Downloads/refind-bin-0.11.2
  5. Re-run this script.

For more on this subject, see http://www.rodsbooks.com/refind/sip.html

Do you want to attempt installation (Y/N)? N
Exiting!

1.: I assume this means refind is already installed, right?

2: Does this mean that by installing ubuntu on a separate partition (I have already created via the Disk Utility) will prompt me for OS selection on next reboot? (provided that ubuntu installation is successful).