To do anything in AdvertCity, you first need some cash. Fortunately at the start of the game you have already been approved for a loan from Happy Banking Corp, the monopoly holder of banking services in the city.
Taking out a loan
To take out a loan, visit any branch of Happy Banking Corp in cyberspace and request a loan, in increments of 10XDG. There is no limit to how much you can borrow, but you will start paying interest on your loan right away! You can monitor your current debts, as well as those of other megacorps in that megacorp's financial summary. A shortcut link to your own summary is one of the buttons in the top left corner of the display.
Repaying a loan
The same way you take out a loan, simply pop by any branch of Happy Banking Corp in cyberspace and click the appropriate button to return your loan, again in increments of 10XDG. If you owe less than 10XDG you will be able to repay that in one go.
It may be a good idea to repay partially any amount of your loan that you aren't currently using, to minimise the amount of interest you pay.
Your debt will grow immediately and constantly based on its amount. Because Dogecoin is an infinitely divisible cryptocurrency (well, almost), your debt can grow in very small increments, but very rapidly. As such it may be worth paying close attention to the rate of growth of your loan, and paying off any part of it you can early on.
If it doesn't look like you are going to be able to afford to pay off your loan, Happy Banking Corp may force you to file for mandatory bankruptcy - at which point it's game over.T
This will happen only if your corporate debts exceed 1000XDG and your available funds are smaller than 1/10th of your debts. It is possible to take out very large loans indeed, as long as you make sure you keep at least 1/10th of your debt in your Happy Banking Corp account at all times as collateral - but do this with care, because loans can quickly spiral out of control!