First off, congratulations on getting such an offer!
To answer your question, this is one situation where I do firmly believe that a short-term loan is called for. Take the signed, formal offer -- it is proof that even though you don't have any money now, you very soon will -- dress up a little if you think it'll help (mostly, this would depend on how you dress normally), walk over to your bank and simply ask for a line of credit associated with your account. If you are about to start earning $5K+/month, then issuing a line of credit for $1000-$2000 should not be a problem at all for the bank. Keep in mind that even after taxes, we are talking about at most perhaps two weeks' pay. In many cases, LoCs also don't charge any interest unless you use it, although there may be a fee involved for setting it up or for simply having access to the credit (much like the fee for a credit card). If so, ask if they are willing to waive at least the application fee, and if they aren't, ask if they can take it out of the newly approved credit.
$2000 should easily pay for a used scooter, some basic safety gear (buy new from a reputable brick-and-mortar store where you can get help picking out sizes etc.!) and gas to get you through your first month, let alone a bus pass if there are useful routes, and after that first month you can pay off the loan with a part of your pay and still have plenty of money left over. A used scooter might not be "cool", but it absolutely will get you from point A to point B with little difficulty. Depending on circumstances, should you get a scooter, you might want to call the company and ask if there is a good place near the office to park it. Don't ask for a parking spot outright; if they can offer you one, they likely will when asked where you can park; if they can't offer one, they should be able to give you good suggestions about where to park.
The interest rate on such a line of credit will likely be fairly high (I would expect on the order of 10%, maybe more if you don't have much of a history with the bank), but if you borrow $1000 at 10% interest and pay it back after one month, the actual interest cost will be around $10 (actually right around $1000 * 10% / 12, minus any applicable tax deductions). As you see, this is such a small amount as to be negligible. (This is not to say that you should use credit carelessly!)
And I definitely agree with what others have said already: don't bring up your financial hardships with the company or even with your new colleagues. This is a temporary situation that you have every possibility of resolving on your own, and getting to and from work is your own responsibility.