Translation:Who wants to work outside with me?
«Со» is a form of «с» used before consonant clusters. Usually it's optional, but before «мной» it's required (and other cases starting with мн-; also before всё 'everything', все 'all').
Other prepositions also have such forms: с/со, в/во, к/ко.
The latter. It doesn't neccessarily mean tidying communal areas. It can mean e.g. working on your own house too.
In case any nonnative English speakers are lurking: be careful translating "in the streets" or "on the street" literally into English—for some reason it is often a euphemism for being a prostitute (of the "streetwalker" class, not in a brothel):