Instruction for custom partitioning during Ubuntu install anywhare?

[Bo Berglund]

I just bought a used HP Prodesk 400 G4 mini PC with 500GB SSD and 16GB RAM and
an Intel i5 type CPU to be used as a server at my summer home.
It has a free 2.5" drive bay too where I will put a 2TB drive I have available
to use as data store.

The seller had "installed" Windows10 on it pre-sale in the mode where you will
be asked to complete installation when it powers up. Apparently it initially had
Ubuntu but all potential buyers backed off when it did not have Windows...

I do not want this at all, I want to get Ubuntu 20.04 LTS (Cinnamon) on it and I
want to completely blow away any Windows stuff on the disk.

So I plan on booting with my install USB for Ubuntu and I know that there is an
option in the install sequence to partition manually.

But last time I had a look there (when creating a virtual machine) I did not
understand what I was supposed to do at all, so I backed off and went the
default path.

Not so this time, but I need to find a valid "howto instruction for Dummies" to
do this:
0) Repartition the whole disk so any Windows stuff is gone.
1) Put the Ubuntu system on one partition
2) Put /home on a separate partition
3) Maybe create a swap partition suitable for the 16GB RAM on this machine
4) Leave some space for future use

Can someone please direct me to some place where this information is available
in an understandable way?


-- 
Bo Berglund
Developer in Sweden