EFI partition appearing when starting mac

Intel Macs are supposed to have a hidden EFI (aka ESP) partition. Since it is identified as "disk0s1", I believe the correct EFI partition is there.

I don't know why you would have created an EFI partition when installing Linux since Linux would just use an existing "EFI" partition. You can manually mount this EFI partition using the following command:

diskutil  mount  disk0s1

Now you can use the Finder to view the contents of this hidden EFI partition. Usually most Linux distributions will create a folder with the distribution's name, such as "ubuntu", but they may also just create a generic & more universal folder with the name "boot". Just delete the corresponding folder and eject the volume. When you reboot, you will no longer boot to the Linux partition. Do NOT touch the folder named "apple". You may also need to perform a PRAM Reset (hold for at least two chimes if possible) just in case the NVRAM was configured to default to booting Linux.

Your screenshot of Disk Utility is perfectly normal. In fact Apple likes to hide things from their users in order to try to make things simpler, but I think it has the opposite effect. Within Disk Utility click "View" and select "Show All Devices" so that the hidden Container and physical drives appear on the left pane of Disk Utility. Even doing this, macOS may still hide the EFI partition from you with certain versions of macOS.

FYI, I never recommend people making multiple partitions on any drive for any reason since it usually causes the user a lot of grief. Many times it is not possible to merge the partitions back into one plus it is always risky to modify partitions since it could destroy data on one or both partitions.

If you want to boot another OS, then it is best to install the second OS into a Virtual Machine assuming your computer has enough resources to run both operating systems at the same time. If your computer has enough resources and you don't need GPU hardware acceleration, then a VM is the best option since you do not have to reboot to access the second OS. If you do need to install another OS onto the bare metal, then install it onto an external drive so that there is minimal risk to the main OS on the internal drive. In the latter scenario, all you have to do to destroy the Linux external boot drive is to erase the whole physical drive and Linux is instantly gone without any risk to the main OS.

and now everytime I start my mac (from sleep or being off) it starts with this particular partition which is empty

What does that mean? What is "this particular partition?"

Do you mean it starts up showing a folder with a flashing question mark?

You highlighted the Snapshot. Is that what you are concerned about? That is how it is supposed to work.

From a M2 Apple Silicon computer

Is your issue the " EFI EFI " " 314.6 MB " " disk0s1 " on an Intel Computer ?

As pervious contributor mentioned, the Snapshot Volume is where the Operating System resides in a and is Sealed and Read Only Volume that can 't be opened by the User nor by Third Party Applications.

Mac-Mini-M2 ~ % diskutil list

/dev/disk0 (internal, physical):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *251.0 GB   disk0

   1:             Apple_APFS_ISC Container disk1         524.3 MB   disk0s1

   2:                 Apple_APFS Container disk3         245.1 GB   disk0s2

   3:        Apple_APFS_Recovery Container disk2         5.4 GB     disk0s3

/dev/disk3 (synthesized):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      APFS Container Scheme -                      +245.1 GB   disk3

                                 Physical Store disk0s2

   1:                APFS Volume Macintosh HD            10.1 GB    disk3s1

   2:              APFS Snapshot com.apple.os.update-... 10.1 GB    disk3s1s1

   3:                APFS Volume Preboot                 6.1 GB     disk3s2

   4:                APFS Volume Recovery                907.2 MB   disk3s3

   5:                APFS Volume Data                    17.7 GB    disk3s5

   6:                APFS Volume VM   

Was a Third Party Application used when the Linux was installed ?

Was The rEFInd Boot Manager installed ?

What is the Startup Disc in your System Settings?