Hmm, maybe it's worth stealing a few UX ideas from Meetup? Your site is civics-focused (which is really cool), but otherwise it's a pretty standard events platform, and there's a lot of design and research that went into the other ones. Specifically:

1) The map takes up a lot of screen space but that's arguably not what is most important in this context. If you live in NYC, I would expect that getting around isn't going to be the make-or-break factor of whether you're going to an event. Meetup doesn't even have a map, and Yelp has a small overview map; both let the actual listings take up most of the space, because that's what people are looking for (interesting events, not primarily the closest one by 0.5 miles)

2) Allow people to browse not just events but also groups (associated nonprofits), along with a brief description for each and a "learn more" link. Maybe even some brief metadata (# of members, # of events hosted in the last 3 months, maybe even user reviews...)

3) You talked about the onboarding process in the works. Meetup is pretty good at that, allowing you to select multiple interests (tags) and showing you only the relevant stuff.

4) Being able to subscribe to tags and/or groups would be awesome. Most users probably would only care about a few groups, not all the events happening around them

5) Your filters are a bit confusing. What is the difference between Government, Voting, Campaigns, and Demonstrations...? Maybe more useful categories would be things like "Public Meeting", "Protest", "Community Gardens", "Arts & Crafts", "Food Kitchens", etc... like the specific activities people can engage in, as opposed to making people try to guess whether an event is more "Campaigns" or "Voting". I think breaking down "politics" into specific subcategories is something that people in the field (on the hill/work for a politician) might do, but to the general public, being able to (for example) separate thanksgiving help at the soup kitchen vs chalking for a politician is probably more useful.

6) For the search bar, also allow broader searches ("protests") and suggest them in the placeholder and autocomplete. Searching by exact event name is useless because there's no way people would know what nonprofits call their events.

7) Have some measure of popularity or importance, whether it's a heatmap or a count of attendees/group size, etc. I think the biggest job (and the hardest thing to do) for events sites is dealing with the signal to noise ratio, and presenting the most interesting events -- whether by algorithm or human moderation -- as opposed to a long list of tiny events with like 3-4 people attending that most people won't be interested in. The default view of a new user shouldn't be, "here's 200 things happening in your town, good luck choosing one" but rather something like "here are 3 top picks for today, and 2 more later this week... plus browse by category or popularity"

Some other minor stuff: Your images are loading with the wrong aspect ratios. They are being forcibly resized to squares in your popups... it's a small thing but has a big visual impact. Your Share button is way more prominent than your View More. Your addresses aren't clickable.

Overall though, really glad to see this sort of thing springing up. Thanks for building it, and hope it takes off!