Before each class I skimmed the lecture to familiarize myself with the content. I went to class. Definitely go to class. The lectures are recorded but when you watch them at home or on 1.7x speed, you never pay as much attention as you would otherwise if you were in class. Professors will occasionally test on content that was spoken out-loud. I annotated PDFs of the PPTs in class. Each day, I went home and typed up the text on the PPT slides along with the notes I added from class. I included the important images from the powerpoint as well. By exam time, I had a long comprehensive organized study guide. This process is time consuming but made me very successful in the classes. I wouldn't memorize every single little detail on the slides--that's not high yield. You can usually tell by the way the professors teach and go through the material what is important is what is supplemental information. I formed a study group fairly quickly and that was extremely helpful. It's great having someone you can study the material with who is engaging and helps bring the content to life. I also diagrammed out pathways (like in biochem and genetics) and always tried to draw connections between the classes. Similar topics are presented between concurrent classes, which is pretty nice and helps to reinforce the content.
In terms of getting ready for exams, cramming will not work. You want to build a foundation for the material early on so when the "cram" of exams comes, you're simply refreshing yourself on the material and filling in knowledge gaps. That's not to say exam blocks aren't stressful. They are stressful, but if you prepare well, you set yourself up for success. Something I did once I had my comprehensive study guides was writing out the material on piece of paper or on a notes app on my iPad. I also would occasionally listen to the audio of the recorded lectures while going running or driving. Download the Panopto app and stream the lecture audio. It's a great way to keep yourself fresh on the material especially around exam time. My technique may sound like overkill and it was really a lot but it worked for me. Everyone learns differently but you'll see what works best for you.
The biggest thing I'd say is start off strong and do not slack off. You should be studying next weekend and starting to form study groups. People are really nice. I'd recommend sitting in different seats of the auditorium throughout the week and just talking to random people. If you do very poorly on the first round of exams, it makes it very difficult to do well in the courses later on. The grade in each class is determined by 3 equally weighted exams. If you do well from the start, it makes it a little less stressful throughout the semester. Also go to the TA sessions, especially when you're struggling with a topic that was covered that week in class. The TAs will have recommendations and will send out links for helpful YouTube videos. The 60hrs a week thing is close to accurate. The week after an exam block, you're not studying 60hrs but in those 9 days of exam blocks, you're studying for as many hours fit in the day aside from eating, working out, sleeping (6-8hrs), and class. It's always better to start out strong and ease off a little than to not study enough and have to play catch up the entire year. A 4.0 is achievable but you have to really want it.