A huge company like Google requires the skills of many, many different people. Google is primarily a software engineering company: we hire lots of engineers who build apps you use on the internet such as Gmail, YouTube, Google Maps, and of course Google search. So if you're interested in computer science and technology and want to become a software engineer, Google is a great place for you to work.
Apart from engineers, Googlers come from a lot of different backgrounds. We hires a lot of people in Sales, so people who work with clients who want to advertise on Google Ads. I work in Communications, where we're responsible for talking to the media on behalf of Google. There are also people who work in Marketing (who tell people about Google products through TV ads, print ads, events), Policy and Legal (lawyers who work with the government and other lawyers to protect Google), and many, many other positions. Basically, Google needs people with all sorts of different abilities and backgrounds, so just find something you're good at and be good at it!