You can use your operating system to search for all JPG and all TIF and all RAW, etc.
You then Import them into Lightroom. Once you have located the files (as explained in the previous paragraph), simply select the files in your operating system and drag them into Lightroom. More details here: Adobe Photoshop Lightroom Help | Import photos from a folder on a hard drive (Select "Add" at the top of the Import dialog box if you want to keep the photos in their current location, and then click on the Import button)
You might want to view some tutorial videos regarding Lightroom at Getting Started with Adobe Photoshop Lightroom 5 | Adobe TV
Good info and thank you for taking the time for such a thoughtful reply. Happy 4th!