1) what is the difference between EE and ECSE and mechatronics ? im more interested in making things like laptops, electronics for cars/planes, department of defense work, robot stuff maybe etc. which of the three would suit me more?
EE deals exclusively with electrical and/or electronic engineering. Since computer science is quite closely linked with electrical engineering, many universities have EE combined with the CS department (like UC Berkeley, where the faculty is called EECS). This is why Monash's degree is ECSE. Basically, EE == ECSE (in terms of faculties and degree names). Mechatronics is a combination of software engineering, electrical engineering and mechanical engineering. This is seen as a robotics degree, however, employment is quite low in Australia so you may need to go overseas to find a pure mechatronics role.
If you want to deal with laptops/electronics, you want to do an Electrical Engineering major with a focus on electronics. If you want to work on robot stuff, either do Electrical/Software/Mechanical Engineering by itself, or do Mechatronics Engineering. It's up to you to decide what you'd like to do. I suggest you take a general first year engineering course (which means you can't do Mechatronics at Monash since it is a seperate degree from the B.Eng) to get an idea of what you want to do.
2) do i need to know how to code for these degrees? i have tried learning javascript and python and stuff but i just dont understand it ! maybe i need a teacher?
You will need to learn to code in all of these degrees to a high level, especially Mechatronics and Electrical, compared to other engineering disciplines.
3) what sort of math and physics knowledge is required? im good at math but not quite at the spesh level and havent really been a super whiz kid at math, i just study hard and good grades follow.
You'll have to complete up to 2nd year mathematics, but if you study enough, it shouldn't be too bad. In terms of physics, engineering is really applied physics, so if you take courses in Fluid Dynamics / Electromagnetism / etc, you'll be learning the physical laws and how to use it to engineer a solution.