IB/AP is a hit or miss thing. It might get you out of some intro english/science/history/math courses but not always. Sometimes universities don't know what IB is. On the other hand, if you want to get into some fancy colleges you're going to want to take higher level classes and do well in them.
However, it's important to know that IB/AP aren't the only options, and this is stuff that your guidance counselor probably won't tell you. Probably for a good reason, because you might jump out there and take more than you can handle and end up failing high school as well. In any case, I would like to point out that there's a couple of alternative strategies to completing high school.
1. Take easier courses and do well. Take college level classes at a community college at night. Make sure the college is accredited and that their credits will transfer to a college first.
The good thing about this is that you get to take higher level courses, and if you do poorly in them, you can just sweep them under the rug and choose not to send your transcript to whatever college you want to go to. Unlike high school grades, you don't have to share college grades with anyone ever, so you can conveniently pretend it never happened if you like and send only your good high school grades to whatever college you're applying too.
Downside is having to take classes at night. Also tuition will probably be around 300-500 a class, without financial aid, which is more than the $100 fee you have to take an AP or IB test. Also the bus won't pick you up and take you to college, you're going to have to drive or find someone to take you there. Also you'll be spending 1-2 hours at college a night in addition to the time you're spending at high schools. I'd guess that all things going well, you could probably finish 4 classes at night over your high school term, taking one class a semester at night your junior and senior years at high school.
2. Take easier high school classes and do well. After graduating attend community college and get all of the introductory classes out of the way, then transfer. Same benefit as AP and IB and it will leave plenty of time in high school and community college for doing stuff other than studying. The drawback is that you're still going to get your BA in four years, if you want to cut out a semester or two stick with AP/IB or the first strategy.
3. Take college courses over the summer. You can get a stuff ton of classes done over the summer semester, but at that point you're basically going to school year round, with high school still going on in the fall, winter, and spring. Still, you're only taking classes 2-3 hours a day 3 or 4 days a week for 14 weeks in the summer, so it's really not that bad.
4. Take bridge classes in your high school. Ask your guidance counselors if they have any. Basically bridge classes are in cooperation with a local college and taking that course at the high school will also give you credit for that course at the college. Bridge classes vary wildly, the courses may only apply to that institution or they may be transferable to other colleges, they may be offered at the high school or you may have to commute to the college for the class, and there may be a fee to apply for course credit although it's lower than paying tuition.
5. Ask about work release. As long as you're meeting the high school's requirements for attendance and taking classes, you don't actually have to have a full schedule. My high school would let you come to school late and leave early if you signed up for work release and otherwise were on track to meet all the requirements for graduation. People ran into this a lot because people would regularly sign up for more classes in place of lunch or study hall. It's great if you want to work, attend classes at a college, or just otherwise don't feel like going to school.
Note that I'm not telling you to do this, just that it's stuff you should be aware of and ask about if you're interested in doing any of it.
