A couple B’s in honors classes Freshman year would not make or break your admission to an Ivy League school. Such schools admit students with B’s on their transcript all the time. But there’s no way to chance someone for such a school Freshman year. Amazing students are declined every year and you have years to develop a more comprehensive profile with your academics, activities, etc.
UCLA does not consider Freshman GPA, so you could still end up with a 4.0 by their calculation. UCLA is very GPA sensitive so you’ll need mostly A’s Sophomore and Junior years (they don’t look at Senior year either).