Monetize Your Blog

Blogger has it all set up for you to start advertising with Google Ads. Select the the Monetize tab. You will need to apply for an AdSense account. This is actually quite easy.
You can select where you would like ads to appear on your blog.

The AdSense will appear as a gadget in your layout.
From there if you want to add more AdSense return to layout and Add A Gadget and select AdSense. You will be given some options of ad types, sizes and color schemes.