Just go solo and unplanned. And of course check some recommendations or blogs on Udaipur (there are plenty on Tripoto). The place is very beautiful indeed so if you take it one at a time, day by day basis, trust me your going to enjoy Udaipur. I'm sure you can check Oyo or some feeling colleague here in Tripoto will be able to give you suggestions for some decent but inexpensive staying options. The city of lakes will not be a disappointment even with a very limited budget. Rajasthani cuisines are not very costly and delicious at the same time if you about those very costly traditional there based eating joints. Best of luck
There are loads of hostels like zostel in udaipur that are very reasonably priced. Yiu can visit hagfish temple, city palace, jag mandir, lake pichola, fatehsagar lake, kumbhalgarh fort, hathipolr market for shopping!!