Can I copy my old drive 1st before I install the new kit I'm buying

Get a USB to SATA adapter.

Put the new drive into the machine and attach the old drive via the adapter.

Boot holding down the option key and select the external (old) drive.

Got to Disk Utilities and format the new drive GUID, OS X extended.

Now install a system and allow it to reboot from the new drive.

Select Transfer data from existing boot drive.

Migrate your data. (If you have a lot, just migrate the User data first and then migrate your Apps.

You will now have a drive with a repair partition on it.

https://www.amazon.com/SATA-Drive-Adapte...