Booting W 7 ultimate to SSD when Data is already on the drive

[Averyius]

I am building a new computer. I have used Rufus software to download Windows 7 64 bit to a stick / pen flash drive. I intend to install on and run the operating system from my new SSD. I want to know if Windows will automatically create a disk partition for me or if I must "expand the volume" (why must they mislead or confuse people by using terminology that is not obvious in meaning?)? When I installed W7 Ultimate 32 bit on my internal HDD many years ago I did not partition the drive. A friend came over and did that for me much later. Windows did not do that for me. I am viewing a youtube tutorial video which shows Windows doing it automatically upon installation. I am confused! If I successfully manage to build all components correctly and install W7, how do I then gain access to all data on my current HDD and use it?
Also is it safe to install W7 to my new SSD when I have already got data stored there or must I move the data to another memory / disk before? Will the installation re-format the SSD before installation?