If you have a credit card, you don't need to worry - much - about how much you spend. You put it all on your charge card, and keep charging until you reach your limit.
But with a debit card it is different. You can only spend the amount of money you have in your account, and no more.
It is imperative, therefore, that you keep careful track of how much you spend each day, and subtract it from your debit card.
Do *not* trust your online banking balance to tell you the whole story! You expect that because you're using a debit card, the money is removed immediately from your account. That is not always the case. Sometimes it takes a week before it shows up on your account.
In addition, be careful when taking cash out of an ATM, as you can get double-dipped here. The ATM will charge you $2.00, because you're using a card outside their network, and your own bank will charge you $2.00, for the same reason! So if you're getting cash, make sure you get enough out at once so that you won't have to do it again for the rest of your trip.
It is possible to use a debit card to reserve a hotel/motel room, and to pay for one. However, some businesses put an extra 15% on the card, for "incidentals." (Such as if you spill ink or something unwashable on a sheet, I assume, and they don't find this out until after you've checked out.)
Here again, you must be very careful. The money in your account is usually debited immediately, but sometimes its not. In addition, sometimes its debited, then "released" (so you think all of a sudden you've got $60 more than you'd thought!) than after another day it's debited again!
I cannot stress enough that when travelling with a debit card, you keep track of your payments yourself, and don't trust your online balance to tell you the correct story.