I would not assume your bags will be first off kind of depends on where you are flying in from and how the baggage handlers work there, but the way I would do it would be to get a luggage cart and walk, study the walk but it isn’t that bad and there are no variables to consider, yeah it will be a pain to push that much luggage but getting it into a cab or on a bus would also be a pain, i assume the United flight is domestic otherwise you run into danger of missing the luggage check in cut off time