creating multiple partitions

Solution 1:

For a modern one-user (or mainly one-user) workstation, partitioning is more a matter of taste than other thing. I commented more extensively here.

If you are sure yo do not want other OS installed (even in the future), I would expand the /home partition to fill the disk (and maybe leaving a bit more space for /, although I never filled it up.)

My normal routine when installing from scratch is to create / and /home, and then moving /usr/local and /opt in the home partition, and then linking them back. Some on the line of (as root):

cp -rva /usr/local /home 
mv /usr/local /usr/local.old
ln -s /home/local /usr/local

and (normally /opt does not exist)

mkdir /home/opt 
ln -s /home/opt /opt

This kind of configuration will let you reinstall another Linux operating system without touching your data (even locally compiled programs will stay under /home/local, and you have to just re-do the links when reinstalling).

Another possibility (quite more complex, but interesting) is to learn to use LVM: : in that way you can resize the partition on the fly if you want.