Hello, Use Hubspot I think it is a great solution if you manage "leads". When I mean "leads" I mean your users fill in a form and you have to do follow-ups and you must have a CRM to track all of that. Plus Hubspot, what you should integrate is a web analytics solution with UTMs to track the visits for each channel. Buffer is a great solution for sharing and schedule content but nothing else. I think here is more what you need to achieve, what is your main goal, what is your job to be done, and then, based on that see if the answer is Hubspot or any other solution. Hubspot they have the free CRM version. They have more solutions and some of them you have to pay for and are quite expensive. Maybe they have a special price for NGOs.

I might be quite broad with my answer, but if you answer those questions, the advice could be more accurate and narrow.

I hope you find useful this answer.

Cheers,