It’s possible you may be eligible for as much as $500 in free Google AdWords advertising.
You can find these coupons by searching for “Google AdWords Coupon”. Take note that many of these coupons are found on sites that would like to sell you Google AdWords advertising help, but you don’t need to buy anything to get a coupon.
Also, here is a site I found that lists quite a few of the coupons. These codes may or may not work at the time you try them, but it is a place to start.
And here is what Google says about these AdWords coupons:
Google Ads promotional code (coupon)
Also known as coupons or vouchers, a monetary credit that can be added to an advertiser’s account once they meet any necessary criteria. Google or our partners will occasionally offer promotional codes to encourage new advertisers to get started with Google Ads.
Most codes need to be applied within 14 days after you first create your Google Ads account.
Google can’t accept or replace expired promotional codes.
Promotional codes work differently with different payment settings, such as automatic or manual payments.
In order to use most promotional codes, your account needs to meet certain criteria. The terms and conditions for each offer vary by promotion, so be sure to check the details in the promotional material.