Your company must have a travel policy. Ask for it.

Most companies require you to pay first and reimburse later, unless you are a very junior staff then you may request for advance payment. Once again depending on your company travel policy. Usually meals, travel, laundry, mobile phone expenses should be claimable. I have meals and drinks at reasonable places although my boss doesn't question me on the few occasions that I go to fancier restaurants while traveling. One of the companies I've worked for went on a per diem basis which was great.

Don't fret over it.. traveling for work is no big deal.