What do colleges look for?

Okay so I am a rising sophmore in high school. My first semester grades were pretty bad- C, C+, B, B, B+. Was about a 2.7 gpa unweighted. all my classes are honors though which I know helps a little. However, second semester, I dropped one of my honors classes to regular and ended up getting an A-. so my 2nd semester grades were B, B-, A-, A-, A-. gpa unweighted was around a 3.4 or 3.5. i heard that good colleges, esp. ivy leagues just like to see improvement. and i definitely have improved and I plan on continuing to improve throughout the rest of high school. so assuming i have a 3.4 or above for the rest of high school, is that good enough for a really good college, maybe ivy league??? plus all the ec and sports plus interview and submission essay?