If you are positive that there is nothing on the hard drive and its your first time to install Linux go for Guided-use entire disk click Continue to let Debian do its thing.
Distros : Debian - Set up the Hard Drive
The trickiest part in any Linux Installation is where to Install the Operating System: which hard drive, which partition, do you run the risk of overwriting important data or another Operating System such as Windows.
If you are unsure, abort the Installation and boot the PC from something like Puppy Linux to view the contents of the hard drive[s] before you go any further, after the next few steps it will BE TOO LATE.

Linux refers to the Hard Drive and the two USB Keys as SCSI Drives:
- SCSI 1- sda - the 60GB Hard Drive.
- SCSI 3- sdb - the 4GB Debian Install USB Key.
- SCSI 4- sdc - the 8.1GB usb key that I am saving these screenshots on.

The Hard Drive is selected, NOTE THE WARNING.
Check out this short article on the Dell Website re their Ubuntu Linux PC's and Device naming conventions.
Now to partition the hard drive...

The easiest option is selected, you can put busy directories such as /home and /tmp in their own partitions or even on separate hard drives for speed and if a disk or partition fails, you don't lose everything. Of course you will constantly backup important Data :-) .
The Installer is going to create a 59GB Primary Partition /dev/sda1 formatted as ext4 and a 1GB Secondary Partition /dev/sda5 formatted as Swap.

If the above is not what you want, select Undo Changes to Partitions otherwise click Continue.

Again the pending operations are listed, note the WARNING and also as a final safety check the Write the changes to disks? is set to No, to press ahead, click on Yes and then Continue.
I have the hard drive partitioned, I just wanted to see how far I could take it before I said NO, So it left it as No clicked Continue and ended right back to Debian’s suggested Disk Layout.

This time I Double Clicked on Undo changes to partitions and returned back to my own layout.

I Double Clicked on the 57GB ext4 partition to edit it. Here you can Resize/Delete the Partition, as this is where I want to install Debian on I Double Clicked Use as:

Here you can choose which file system to use, I am sticking with Ext4

Back at the editing partition page I Double Clicked on Mount point: and in that page choose the root file system as I want to keep it simple, everything bar Swap in the one partition

Back again at editing partition I gave it the Label Debian 10 and then Double Clicked on Done setting up the partition

Above is the setup I want, The Dell Utility Partition /dev/sda1 will remain, I have a swap partition in /dev/sda2 and Debian will be installed in /dev/sda3, three primary partitions, keeping it simple.

Again I Double Clicked on Finish partitioning... which brings me to this WARNING: but this time I selected Yes!!!.
Debian did its thing and finally its time to install the Operating System and Software.