Oh, and side note—once you've started generating a decent amount of traffic to your blog, it'll be a smart long-term decision to move up your hosting plan to a managed WordPress hosting provider like Kinsta that have even more features (which is what I use now that I'm in the hundreds of thousands of monthly readers), especially when you're in need of speeding up your WordPress blog.
Working with advertising networks isn’t your only option when it comes to selling ads. If you end up with enough traffic, advertisers may come directly to you and ask you to place their ad on your site. You can also contact advertisers yourself. The biggest difference from the above mentioned option is that there is no middle man, which means you can set your own ad rates.