The first part of this step is to download the software. Go to the Official Bitcoin Website. In a box at the top of the page, click the software version that applies to your given OS. The steps are the same for both Mac and Windows users, other than installing different software. Open the file and follow onscreen instructions.
When it is done, open up the software from the Start Menu. It will take a few hours to download all blocks to your computer. You must just sit and wait during this time (see pictures).
When it is done downloading the blocks (don’t worry about what this means; it’s not important), go over to the “Receive coins” tab up at the top. Right-click on the one existing list item, and click “Edit”. Give it the label “Main” and hit OK. Right-click on it again and click “Copy Address”. This is the unique address that your wallet was given. It is where you receive coins in later steps.
The next step tests out your bitcoin wallet and shows you what a transaction looks like.