Delighted to help you, stormi180. If you go to the large apple icon at the top left of your screen, then go to “about this Mac” then system report/more info, then hardware, it will tell you if you have a wifi and/or a bluetooth card installed... if that’s a “Yes”, then proceed...
wifi is not turned on by default. If you go to system preferences, then Network..you can turn on and turn off wifi yourself. You also have to set up your own Wi-Fi network with your own password, etc. Click on the plus button to create a Network.. then choose the type... Ethernet /Wi-Fi/etc. Make a Wi-Fi one.. .. If you click on the” Advanced” pane... you can create a 5Ghz rather than the default 2.4 Ghz one, which might be more subsceptible to interference. After you have done so, for both, click on Apply, then quit and restart your MacBook. After it starts up, at the password login screen, you should see the Wi-fi icon and it should be lit up. If you find, through “About This Mac” that you don’t have a wifi card, or that it is not working, it is a simple matter to replace either the internal wifi card or the bluetooth card, or both, or you could go for the easy approach and get a USB dongle for your Mac that does/supports wifi and bluetooth. Just look for one that has the words “supports Mac OS X” on the package.
that’s it
good luck
John B