Hey, i’m to apply to some colleges and universities this year, but i think i have lack in my ec’s, because of a lot of factors, anyway if i’m going to apply for business program, and i take some courses in that field at coursera or edx with certificate will it enhance my chances of admission ? i also two leadership positions as EC’s too 
It’s a fact that having additional certificates connected the applying course have great value in terms of serving increased chances to get accepted your application.
“great value”? I’m leery – what is the source of this “fact”?
The OP has asked about applying to ultra-selective schools – Ivies that meet full fin aid for internationals. To even be viable, the OP needs to be among the handful of the VERY TOP students in his/her country. I HIGHLY doubt having taken some courses will propel him/her unless he/she already has the top GPA, test scores, and other high honors.
What is adding “great value” to an admissions pool with about a 1-2% admit rate?
I assume SteveJones is either being sarcastic or is just operating on some vague rumor. If you are an international applicant, admissions here knows that you don’t have the opportunity to engage in ECs the way American students generally do so the expectations are different. You will still be help to the same or higher academic standards (depending on the selectivity of the school.)
Remember too that ECs don’t have to clubs or organized activities. Any activity that you engage in and are committed to would meet the criteria. Hopefully you’ve acquired some level of expertise or made an impact or achieved something but it doesn’t have to be externally validated either. I’ve interviewed candidates for a highly selective school who were painters, drew comics, gardeners, cooks, hikers/mountaineers, helped run family business, repaired old cars, did yoga regularly, etc…It was the intensity of engagement, their expertise and enthusiasm in sharing that impressed and made them stand out. What do you love to do?
If i apply to those colleges, will i be compared to american applicants or international applicants or applicants from my home country ? @N’s Mom i love to program, write stories, i play sports, (soccer and swimming, running ) those are my favourite,i also like to learn new things i don’t care if they are in the field i’m interested in or not, i’m open minded for learning, i like computer science, i’m a bit amateur on that field, i want to design app one day, i like the job i had, working at a store, i think i’m going to take a gap year to experience online learning…i like teaching and helping people, i also like volunteering especially for non profit organisations.
You will be compared to international applicants from your home country.
If there are multiple applicants from your school, you will also be compared to them. That’s the purpose of the guidance counselor’s letter of rec, by the way. It helps schools compare students to others in their class who are also applying to the same school. It also explains what kind of resources a school has in the school profile - for example, do they offer AP classes? A few or many?
As for your ECs, you don’t need a list of 10 just because they give you 10 spaces. Pick the those activities in which you are most invested personally, those where you have achieved something of importance (in your own estimation), and where you have something potentially to offer the school community that you would be joining.
As for taking a gap year to take on-line courses, I would only do that in conjunction with some other activity. Taking the classes in themselves won’t make you more attractive, even with the certificates, unless you are doing it to work towards a goal of some kind. For example, if you work for a non-profit providing tech support, you might take an on-line class in web design that either helps you help them with their web-site, or your work with them has triggered your interest in learning more in-depth about web design in general. Simply sitting at home taking a bunch of on-line classes won’t do you any favors.