this is kind of hard to fully get your head around with no calculus knowledge, but it will all become clear for you eventually (unless you only do general maths). But you should be able to deduce some fundamental things.
On a displacement time graph, the gradient gives you the velocity (ie the amount of distance per unit of time). If you think about it, this makes perfect sense because the gradient gives you the rate of change of something, and velocity is the rate of change of displacement.
Once you have the velocity time graph, likewise the gradient gives you the acceleration (the amount of change in velocity per time)
going the other way requires an understanding of calculus, using a process called integration which isnt covered until year 12 2 unit maths, so ask your teacher about what you really need to know.
But you should be able to have some sort of rudimentary knowlege of it - ie from an acceleration time graph, it is impossible to determine the velocity without extra information. Think about it - if you are told that the acceleration of something is zero, there is no way of knowing whether its velocity is 1ms
-1 or 1000ms
-1....
Hopefully this made some sense - at first these things can seem very foreign but you get used to them as you use them again in year 12 physics and in year 12 2unit and 3 unit maths.
feel free to ask anything else if you're not sure
