Where can I see logs of failed system startup and crashed drivers in Ubuntu 18.04?

Question

ubuntu

After unsuccessfully installed updates, ubuntu 16.04 stopped running correctly on my laptop.
After pressing the power button, the manufacturer's logo appears, a black screen, then purple and then freezing.
I can log into the system in recovery mode after a forced reboot - I checked the broken packages and the file system there, everything is ok. From recovery mode, the system boots correctly, I can log in.
I read that the origins of this problem are in a broken Nvidia driver, demolished and reinstalled fresh and stale drivers several times (via the GUI and via the terminal in recovery mode before logging in), tried to completely switch to Nouveau - to no avail.
Updated to Ubuntu 18.04, installed latest recommended nvidia drivers (455) from Software & Updates > Proprietary drivers menu. Some glitches are gone, but the main problem - a purple screen without switching to the login window during a normal start, remains.
The problem is that I don’t know how to view the logs correctly - in the terminal mode in recovery mode, I tried to look through less and cat journalctl -b, /var/log/boot.log, dmesg- it was impossible to scroll, the laptop immediately went into errors and rebooted. If you successfully enter the GUI after starting recovery mode, there are no errors - everything is [OK], and the old startup logs are not visible.
UPD. In syslog and xorg.0.log, I also do not yet find an error that is specifically related to the graphical shell file.
Looking at which logs will help pinpoint the problem? Maybe I'm missing something?

Output of sudo lshw -c display

[email protected]:~$

sudo lshw -c display
[sudo] password for dariia: 
  *-display UNCLAIMED       
       description: VGA compatible controller
       product: Skylake GT2 [HD Graphics 520]
       vendor: Intel Corporation
       physical id: 2
       bus info: [email protected]:00:02.0
       version: 07
       width: 64 bits
       clock: 33MHz
       capabilities: pciexpress msi pm vga_controller bus_master cap_list
       configuration: latency=0
       resources: memory:dd000000-ddffffff memory:b0000000-bfffffff ioport:f000(size=64) memory:c0000-dffff
  *-display
       description: 3D controller
       product: NVIDIA Corporation
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: [email protected]:01:00.0
       version: a2
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list rom
       configuration: driver=nvidia latency=0
       resources: irq:16 memory:de000000-deffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:e000(size=128) memory:df000000-df07ffff

UPD2. Command output
journalctl -b -p3
journalctl -b -1 -p3
lspci -k
link to gist with logs