I have just taken my first dose of propranolol and I don't feel too good what should I do?

Ask the doctor. Speak with the doctor who prescribed the medication. If you mean really bad when you say not too good - go to an er. Here is a loooong list of side effects to help you decide if you need fast or slow help. I wish people could be better educated about their meds - the whys? Hows? And side effects and alternatives. This may be a start for you. http://www.drugs.com/sfx/propranolol-side-effects.html.
Dirnk gluids, rest. Propranolol can lower blood pressure (BP) and heart rate. Lowering the BP can make you feel tired, washed out, lightheaded. It can also just make anyone feel tired at first. Drink plenty of lfuids to counteract impact on bp.
Not unique. Propranolol is a beta blocker, and has numerous nasty side effects, including asthma, depression, fatigue, exercise intolerance, slowing of pulse, dropping of blood pressure, and cognitive problems (memory). I do not use this medication in any of my patients due to the adverse effects. If you need a beta blocker for cardiac issues, other newer meds have less side effects.
Depends. Can't give you specifics because it depends on what you're feeling. Check your blood pressure and heart rate. If either is too low, call your doctor or go to the er.