Hey there, those rule of thumb-thrust settings (fifties for Flaps 30, sixties for Flaps 40) are good to check if youre in the right region, generally you'll be alright speedwise if you stick to them, the rest is stick and rudder skills, same with the engine failure - the 737 is a lot tamer than a piston trainer, use the same skills - failure shortly after rotation: bank the aircraft onto the failed engine, 'lean' over the runway and keep the track line in the middle, then slowly reduce the bank while giving more and more rudder. Trim as soon as you can to at least five units to prevent your legs from shuddering
You'll be fine... after all its a course, there should be an instructor to help you along if you encounter problems - good luck!