[kuhewa]

You might be being a bit too vague here for a lot of operational advice, but from what I gather both projects are contingent on a lot of user uptake, but you have no budget. Especially the first project since it is a social app and will require a minimum userbase within a city to be useful. the second you are unsure if you have a "clear business model" or if "business-wise not so [well defined]" and the purpose is not clear to you.

Might I suggest pursuing neither right now, and identifying a smaller project that won't have a minimum threshold required for any commercial success (that might be impossible to reach without a marketing budget or tons of luck)