Not much to worry about other than the Gypsy kids - watch your pockets, personally I just tell them to f off. Most people there speak English so language isn't a problem. I used to go over every couple of months, and I had a cheap mountain bike there that I used to ride around on. I got to know the embassy and main park area on the OTP side of town really well. I fact I can find my way around most of that side of town with no problem. Last time I paid about 40 lei for a taxi from OTP to where I was staying (less than £10). I've never taken a tram or a bus.
It's an incredibly depressing city if it rains - Ceausescu pulled down a lot of the historical buildings and put up eastern European concrete block flats everywhere. Budapest is much better - I really like the town there. Not that there aren't things to see. It is a city of big contrasts, the poor are really peasants, they walk everywhere and grow their own food. However the rich there are extremely rich, you will see all the most expensive car makes there. The food is pretty good, but avoid some of the Romanian specialities like tripe soup - it is sour and nasty. Lots of Pork there (McDonalds serve a McPork!). Pizza is good there (many of the chefs are Italian). If you are near the park, Quattro Stagioni has great food and good views and is between the Arcul De Triumf and Charles De Gaulle plazas at Herastrau park.
Which airline are you taking - if it is Wizz, then pay the extra few quid for the aisle seat.