I've been using duckduckgo for half a year already they've became quite good compared to Google search, Google maps alternative is any popular maps app just try what'll fit your tastes, but YouTube is certainly don't have alternatives YET just because libre alternatives though exist but not yet in shape enough (basically we need datahoarders who'll hoard and host whole youtube to libre alternatives such as framatube and others) for now we can only rely to custom frontends such as clipious, piped and others and custom apps of course