Congratulations, you're doing great.
What version of win 10 you have, Home or pro?

Let's create a new Recovery partition on the unallocated space
diskpart
Sel disk 0
create par prim
format...

Next step:
- Boot from Win 10 USB installation drive
- delete partition 3 and 4
- Shrink C: in 450M

Boot from a Win 10 installation drive and at the Windows Setup screen, press Shift+F10...

Open a CMD window as administrator and type:
bcdboot C:\Windows /s W: /f UEFI

Sorry, it is C: not G:

Why partition 1 has no Letter?

Open a CMD window as administrator and type:
diskpart
select disk 0
select part 1
assign letter=w
exit
bcdboot C:\Windows /s W: /f UEFI

Next step
- Delete the System partition and create a new EFI partition on it.

Open a CMD window as administrator and type:
Diskpart
sel disk 0
sel part 1
del part override
create part EFI ...

Next step
- Delete the System partition and create a new EFI partition on it.

Open a CMD window as administrator and type:
Diskpart
sel disk 0
list part (it will list all partitions on disk 0)...

try to run as administrator on a CMD window
shutdown.exe /p

Boot from C: as UEFI

So my suggestion is to shutdown, set BIOS to boot as UEFI and boot from it.
Once booted, lets delete the System partition.

Did you created the Win 10 USB installation drive on it?

Why is drive 2 set as active? Did it once had Windows on it?

Pentagon, why are you creating / loading the WinRE if the partition needs to be enlarged?
S.. happens when the hands goes faster than the brains.
I like to do things step by step.

The MBR2GPT was successful.
The first system partition can't be deleted because the computer booted as Legacy-MBR using the system partition. Once you boot as EFI-GPT you will be able to delete it....

Please edit your profile with ALL your hardware specs. It will help us to help you
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Do you have a SSD or HDD as the main drive?

Regarding the Recovery...

Add or Remove Keyboard Layouts in Windows 10

Partition letters are assigned by the OS. If drive 1 has no Windows on any partition you can delete the partition.

The recovery partition should be at least 850M
KB5034441: Windows Recovery...

The instructions on the post above are easy and simple.
The down side:
- The EFI partition isn't the first
- There is no MSR partition
- There is a EFI partition between C and the recovery...

If drive 0 is GPT you can just create a EFI partition and load the boot manager on it.

diskpart
select disk 0
select vol c
shrink desired=100
create part EFI
format quick FS=fat32 label=EFI...

Read my post 23

What do you want to do?

Open a CMD window as administrator and type:
diskpart
list vol
exit

The boot device is disk 0 partition 1 (Windows partition)
The boot manager is on the System partition (Disk 1 partition 1)

I suggested on post 8 to do a clean install as UEFI-GPT. All partitions will be on the correct sequence
408947

or

I can give you instructions on how to create a System partition on drive 0,...

On a Legacy-MBR, BIOS transfer the boot sequence to a drive MBR that will transfer to a master boot manager on an Active partition (drive 1 - System partition). This master boot manager will transfer...

On a Legacy-MBR the boot manager is on a partition set as Active. From post one the active partition is on the System partition on drive 1.

If you detach drive 1 and 2 can you boot from drive 0?...

Bad things happens when the hands works faster than the brains.

Once again, a boot able GPT drive needs a EFI partition.