Well as with all engineering you can attempt from the ground up in terms of work.
However, many things will be new to you and you will have to work really hard for it. Electrical Engineering can be very fun and rewarding if you enjoy the work you do.
As for what's relevant to electrical engineering, the following topics are ones from Physics which you will require a lot of after first semester (you won't require much about these in first semester of uni as you tend to do more generic engineering courses, but will require them later on in second semester of first year and beyond):
- World Communicates
- Electrical Energy in the home
- Motors and Generators
- Ideas to Implementation
These ones are relevant to Electrical in terms of Physics, but because all Electrical Engineers have to do physics involving kinematics in first semester, you may find the topics Moving About and Space helpful for your first semester of uni.
For the mathematical side of things, 2U is good enough and you can learn the rest as you go. However, I really urge you to learn how to become proficient in 3U/4U calculus and know how to manipulate complex numbers and use them as a form of representation. Complex numbers and calculus are a must for electrical circuits and you will need to be proficient with them as soon as you do circuit analysis.
As for the rest of the maths involved, it will most likely be dedicated to your first year physics courses, which will require mostly mechanics from MX2 and mechanics in MX1. You should be fine learning it at the university maths rate and many people do it fine after having a 2U background (although it is a really tough situation to be in). As for the physics, a slight background in some things from those modules outlined above would be good.
If you have any other questions relating to Electrical Engineering, feel free to post them here and I will answer.
And inb4AD meant "in before anomalousdecay comes and answers"