Just as Rudge says, do an install and tell it to take over the entire disk.
That is too easy though. How about making it more difficult? (If it goes wrong back to Rudge's advice)
Suggest you do a custom partitions for fun rather than accepting the defaults. When it gets to that part of the install try the custom partitioning bit. Then you have to decide how to chop up your disk.
Say 8-10GB for root / is plenty
Say 1GB for swap
?? /home? Separate partition or the rest of the disk? If you are just saving settings then say 5GB is too much
Balance to something like /data
Ext4 is ok
Its a learning process and at this juncture the thought of partitioning your system will most likely terrify you, so go ahead and do it. If it goes wrong reinstall and do the easy take over my entire disk as Rudge says. (or try again)