Hoping to get some help understanding how I can best connect an external hard drive to my laptop, the laptop to a receiver (receiver has Bluetooth and WiFi), the receiver to the TV so that I can watch movies that are stored in the hard drive.
If your receiver supports streaming (check for "DLNA" support), you can keep your laptop where it is, and install a DLNA server (many people recommend Plex, but there are many others). Otherwise, plug laptop directly into receiver, mirror its screen, and use wireless keyboard/mouse combo to drive it.
Another option is to use eg Chromecast plugged into the receiver, and cast movies from the laptop.
Alabalcho's advise is the simplest way but I would set the TV as a 2nd display or extended desktop rather than mirror the laptop screen. That won't let you adjust the screen resolution independently. I also find that I like having the laptop screen available. For instance you can have VLC running on the TV and be looking at the files on the drive at the same time.