Thank you both Cphusion and dalto, the suggested solution works as intended.
I have opened /etc/fstab using nano
sudo nano /etc/fstab
and saved my changes with [ctrl]+[s] afterwards.
I added the line suggested by dalto, each of my NAS folders got a separate line. The addition was done at the end of the file.
192.1xx.xxx.xx:/volume1/folder1 /mnt/nas/folder1 nfs x-systemd.automount,x-systemd.device-timeout=10,timeo=14,x-systemd.idle-timeout=1min 0 0
systemctl needed to be reloaded due to the change:
systemctl-daemon reload
after reloading, mount everything at once listed in /etc/fstab using:
sudo mount -a
The mounting now works as intended, thank you for the help.