To solve this problem, I chose the "Do Something Else" option. I had already cleared out a Partition in Windows using Disk Manager to shrink my main volume.
Now when I choose "do something else" I have free space available.
I made a few partitions:
Type SWAP greater than or equal to the size of my RAM
Type EXT4 with a mount point of / which I gave 15GB - Where your programs and OS will go
Type EXT4 with a mount point of /home which I gave 30GB - Where your personal files will go
Type EXT4 with a mount point of /boot which I gave 250MB - Boot records
I believe you only NEED the "/" out of those. Make sure you are selected on "/" when you click "Install Now"
How large should I make root, home, and swap partitions?
Above is a good answer about the partitions
Why it doesn't have the install along-side option, I don't know. But I see this most commonly with UEFI set-ups. Either way, I prefer the other option anyways because you have more control.