I got two B+s in sophomore year H Alg 2 & H Chem, but I was transferred from a not-so-competative public high school in another area and my current school is extremely competitive (send ~30 kids to ivies every year).
Will it ruin my chance getting into Ivies? Just be honest with me if the answer is “yes”. 
@0x0001 No, it won’t ruin your chances. The college process can be challenging but not terrible. You shouldn’t be stressing about these things already. I was accepted and I had 3 Bs from freshman through junior year.
Do you even know why you want to go to an Ivy? You posted this in the Cornell thread, but if you don’t have a specific #1 Ivy in mind that tells me your just applying for the prestige and not the program. That’s the wrong reason. Anyway, I digress.
Your overall GPA and SAT/ACT test scores are much more important than a couple of Bs. Are you still a sophomore? If so, finish sophomore year strong, then hunker down and take a few APs your junior year and crush them - get all As if possible, but a B in an AP won’t kill you either. Don’t overload yourself though. If your school offers 7 APs you junior year, take 5 not all 7. Enjoy life. They want to see academic rigor but too many kids overload themselves and then you run the risk of more Bs and even a C or two.
The point is, your junior year is the most important year when it comes to Ivies, especially if you apply early decision somewhere because up through junior year is all they have to go by before acceptance.
Also work on meaningful extracurriculars - especially this summer. Use this summer and next to develop a passion for something - whether it be volunteer work, or a professional internship, or a project in your intended major.
The admissions process looks at you as a complete person, not just the grades on a transcript. A few Bs won’t hurt if the rest of your profile is strong.
@cotopaxi Thank you for explaining! That really helps.