Bladder cancers usually do not cause any symptoms unless they are advanced or large and irritate the bladder.
They can be a cause of symptoms similar to those occurring with a blockage to the flow of urine as occurs with a large prostate where the patient experiences a frequent and urgent desire to pass urine. This is why you may need several investigations to determine the cause of your symptoms.
Bladder cancers may also cause painless bleeding that is noted in the urine. This is why blood in the urine always requires evaluation by a Urologist. There are many non serious causes for bleeding but cancer obviously needs to be excluded.
Some bladder cancers are identified as incidental lesions when a scan is undertaken for other reasons as part of investigations for other issues.