Step 4: Match fonts
First, crop your image so that you have just the text (see example image below). Save that and upload it to What The Font. Make sure your image fits within the minimum and maximum size for What The Font. Detailed instructions are on their site.
The site gives you the opportunity to identify letters it's having trouble with so it can present the best guess as to what the font is. Make corrections or change cases as needed.
On the results page, What The Font usually gives more than one match and lets you decide which is the best. Make note of all your fonts...
Hopefully they're fonts you have on hand. Personally, I collect fonts for projects like this and keep a pretty large library of them around. However, once you know the names of the fonts you need, you can forgo building a collection and just buy them piecemeal. Most projects wont have more than 3 fonts. Hopefully they're cheap!