Well, for what understand by “noob”, i think you havnt meet the Blender gamengine yet.
Im quite sure i can help you with your 1st question about the rolling cilinder.
Start modeling the ramp and the cilinder. Now press P key: that will make the colors on the screen look strange, and thats because you have entered the phisics mode, where object behave emulating phisical world (but you havn’t made these arrangements yet, thats why the ramp and the cylinder just remain there, still).
Switch back to normal mode (Esc key) so to start defining the physical aspect of the cylindes. Select the cylinder and sitch to Logic panel (by clicking the little purple packman-like icon or pressing F4);
in the logic panel (and with the cylinder selected) pay atention to the left most part of it, those purple buttons, leftmost one reads “static”, referring to the cilinder as a static element. Sitch it to “dynamic”, that will assign phisical propertys such as mass and weight to the the cilinder.
Now press P and youĺl see that the cilynder falls down, victim of “gravity”.
Then go back to normal mode (Esc) and move your cilinder directly above the ramp. P again to see it (the cyl) fall down and bumb against the ramp, then roll down along it.
The gamengine is a HUGE tool,a world by itself, and o think you can make those others thing about fluids you mentioned above, just get documentation about it.