It's important to realize that just because an ad is not performing well, you failed. It is all about testing! You have to consistently try different phrases, different call to actions, different landing pages, and keep track of what has worked the best, and continue till growth starts becoming exponential.

One of the most important tools you will need to learn how to use to be successful is, Google Ad-words.

When you first start investing money into pay per click ads, the first few hundred dollars is just education money. It's an affordable way to learn marketing in the real world.
In order to fix a sales funnel, break it into sections and fix each part.
The secret to everything is split testing.
Improvements in segments of sales funnels multiply.