Need Advice on what to do over the summer. [Beginning Undergraduate]

I have just finished my final exams and I am about to start into a Physics and Maths degree. I am looking for recommendations and advice on how to best prepare myself for this as I would like to reach my full potential. My classes for the next semester include

• Mechanics and Relativity
• Calc 1
• Intro to Mathematics
• Physics Lab 1
• Linear Algebra 1
• Physics of the Quantum Universe

On another note this is a 3 year degree and continues on from September till July so avoiding burnout is another big priority. Also i'm curious is this even possible, I am of average intelligence but very interested in both physics and maths. Any Advice or insight would be greatly appreciated. Edit: Sorry cannot wrap my head around the formatting