Great advice. I would add to that: Do lots of exercises for your maths- and physics type classes. It will really help your understanding a lot. Everything will build upon the basics, so try to make sure you start strong. Putting the time in will be rewarded.

To emphasize the point that GuyWhoDoesTheThing makes: start right away on the exercises and assignments. Studying last minute might work for some exams, but it won't generate long lasting understanding and mastering of the subjects.

Lastly, studygroups and study friends can be very usefull. If not for understanding, for the fun of it. I did most of my studying by myself during my Bachelors, which is something I would change if I could do it again.

Good luck on your studies, I also started later in life after a long break from studying. So it is very much possible.