I spent several years in the ad business -- both in the "back stage" perhaps less-known process (broadcast media) as well as an account executive. For the creative, dynamic, energetic individual, it's very rewarding and has a great many paths and potential opportunities, not to mention transferable skills (creativity, time management, people management, collaborative, presentation skills, project management, editorial, etc). When you say you want to "make ad campaigns" do you mean you want to be directly involved in creating the ads yourself (for example, there are copywriters - who write the copy) and there are creative directors (who dictate the ad direction), then you have creative teams (who come up with the slogans and the storyboards, etc). You also have Account Executive teams who basically are the key bridge people that make it all happen. It's the kind of position that requires extreme attention, collaboration, time sensitivity and organization. The Account Executive is basically the middle man between the Client and the entire ad team and is in contact with everyone ensuring everyone is working on time and getting it done from initial client request through complete execution of an ad. It's a great position if you want to see ads made and want exposure to every part of the ad making process but don't have the skill set to draw, design or write the copy.
Don't dismiss lesser known areas such as media and broadcast teams (someone has to sell those ads or negotiate time slots and where ads go!) These are more analytical/research positions and more focused on marketing and planning of ads.
Another GREAT way to get into the ad business is to start as a junior level or INTERN in the traffic department. The Traffic department is the team that basically "runs around" with the ads and takes them from the creatives to the account team to the copyeditors, etc etc and I've seen several folks that started in Traffic prove themselves and easily move on to more important, creative roles within the agency. Best advice is to try and INTERN, great way to get your foot into the door. Look for Summer Intern positions at ad agencies near you.
In the meantime, have a resume, prepare yourself and keep tarck of some of the ads you love, things you don't like, get informed and research this space. It's every changing, especially because what used to be traditional (television, outdoor, radio, print) is getting revamped quickly with the entire digital age -- lots of new opportunity.
Good luck to you! Please let me know if you need any help with resume wording or marketable skill set terms.