If you're just testing why do you need it on the internet? Just install apache on your own computer. Or if it's a PHP site use WAMP (windows) or MAMP (mac).
The reason for not having a free site with ads is two fold:
- it's not very professional, having big flashing ads on your website
- some less reputable ad servers are full of spyware and trojans
And you have no control over the content of the ads....think worst case scenarios.