(I’m new on this site and I’m not sure if this is the right place to ask questions, and I apologize if I got it wrong.)
I’m in my second year of high school, and I’m wondering if it is generally true that one needs at least 7 good advanced placement scores to be competitive in college admissions, as I have seen online? I know there are other factors, SAT, GPA, etc, but in terms of AP is 7 a bottom line safe number? Thank you.
It depends on what your school offers. I’d take what you see on CC schedule-wise with a grain of salt.
If colleges see that your school offers 16 APs, and you only take 4, well then we’ve got a problem. 
This question is best asked of your guidance counselor. In part it depends on what classes your HS offers and what types of colleges you are hoping to attend. For the most competitive colleges you want to have a sufficiently strong schedule so your guidance counselor will check the box on the recommendation saying that you have taken the most rigorous schedule available at your HS (which does not necessarily equate to taking the most APs you can).
@mohammadmohd18 is absolutely right. Colleges take a look at how many AP classes are offered at each HS. A student cannot be dinged for only taking 4 if the HS only offers 4. They do want to see a student take advantage of the rigor offered, however.
D’s HS offered around 14 AP classes. Her college counselor put the levels of rigor in tiers, 7-8+ being more competitive. D wound up taking 6, the theory being that she didn’t want her GPA to suffer by overloading herself (along with work, EC’s, 2 sports, etc.). A neighbor who is a vice principal at a very competitive public school in our area also advised her not to overload herself (and that HS had over 40 kids graduate 4.0 unweighted, so she has seen how crazy it can get). D graduated with a 4.0 unweighted and now attends Cal and had a very successful first semester.
It’s all about balance. 10 AP’s aren’t going to impress if you get middling to low grades in them. You have to gage what your bandwidth is so that your GPA and cherished EC’s don’t take an enormous hit. I have seen kids overload on AP’s and quickly find themselves drowning. They give up and wind up going to schools well below where they were originally aiming. Could D have gotten into higher level privates with another AP class thrown in there? Maybe. And maybe it would have been enough to negatively impact the other areas of her life and make her last couple of years of HS miserable. Only YOU know what you are capable of. My only other suggestion is to take classes you are interested in or you feel that can really help in your area of desired study. If you hate the class, you probably won’t do well.
Thank you, happy1 and mohammadmohd18 ! Well, though I am able to take some rigorous courses at my school, it only offers 2 AP courses, in calculus and physics, which I will take next year. In this case, may I ask if it would look better to colleges for me to take a certain recommended number of APs outside of school, assuming that I can manage with the schedule?
Thank you, Undercrackers, and congrats to your daughter! I’ll definitely follow your advice.
May I ask you, if you can estimate, is it possible to ‘make up’ a bit for GPA with AP, since both represent the commitment of the student? I know you can’t really substitute one for the other, but last year, my unweighted GPA was 3.7 or so 
More APs is definitely more doable than a 4.0 for me.
I see no reason to take more APs outside of the school. It is NOT a race where whoever has the most APs wins! The time can be better utilized (academics, ECs, reading, relaxing with friends & family etc.)
If your school only offers 2 APs, independent study for AP tests will show initiative. Come junior year, you should find a couple of APs that interest you and self-study them, then take the AP test(s) (you’ll have to register and pay a not-insubstantial fee).
Or, you could take classes at your local CC. Either way, you will impress adcoms if you go above and beyond what your school offers. It’s one thing to take 10 APs out of the 16 that your school offers (arbitrary number to illustrate my point), and quite another to take the equivalent of 5 or 6 if your school only offers 2.
[This thread](Self-Studying APs: Improving Your App - AP Test Preparation - College Confidential Forums) will teach you a thing or two.
Good luck.