There were many challenges. As when I started meetup and community was not an acceptable thing in India. For me, it was like I am explaining the folks first what meetup is and then doing tech-session. Also, there were no resources to host a meetup at any place. We did our starting meetups for a year at a cafe where I used to pay for venue and food. Apart from logistics challenges, even attendees were not keen to spread the word about the community.
Now, everything is sorted. Every company now supports Meetups and communities and so is co-working. So, there are not many challenges.
My advice :
1) Do not look at how many people came? Look for how many interested people came. At JSLovers, I never focused on having 50-100 folks. My focus was on quality over quantity.
2) Getting speakers is hard. Try to push from your attendees to be a speaker (but do not compromise on the quality). Do a dry run with them, ask questions to them, and also be prepare might be you need to chip-in while speaker is giving session.
3) Have a code of conduct always
4) Do not be afraid of taking negative feedback.For me, feedbacks are my next steps :)
5) Always remember the community is about 'sharing' not about 'marketing'.