Error -bash: vagrant: command not found

I am using iMAC and here is what I did:
step 1: I download virtualbox. (Just download and don’t know what else I need to do)
step 2: I download Vagrant . (just downloaded)
setp 3: I download the class handout and copied the zip file to the my home directory/m103 folder
step 4: I navigate to the handout directory m103-vagrant-env in my terminal and run the command:
$ vagrant up --provision

Step 5: it show the following error:
-bash: vagrant: command not found

What did I miss here?

Any help is appreciated!

You need to install both Vagrant and VirtualBox. You downloaded the installers; run them.

Thanks Tess! I am good now!

Your help is highly appreciated!