I’m an aerospace engineering major in my freshman year, and am taking Calculus I this semester. For next semester, I have the option of taking Calculus II online or in-class. For Calculus I, so far, I’ve had more success understanding the math when reviewing it on my own or with friends. I’l be registering for next semester in a few weeks, and wanted to plan out my schedule before my academic advising. Is it a good idea to take the course online next semester? I don’t want to overburden myself, want to thoroughly understand the concepts of Calc II, and be able to do well on the exams.
That depends on the quality of your online course, your classroom course and what type of learner you are. I’m not sure anyone could answer that except you.
I recommend taking a butt in chair class but using online tools as well.
If you have problems with Calc 2, can you get real time help right away? do you have any friends also taking online? do you have study group with kids taking Calc 2 so that you can also get some type of help if you are stuck? If you can not answer these questions then I believe you just need to take in-class instruction and try to come early before the class starts; so that you can sit at the front row whereby you can raise your hand if you are stuck.
My son is at UF . . . he did pre-calc and Calc 1 online at UF as a dual enrollment student; did very well. Now that he’s at UF as a regular student he is in Calc 2 in a traditional class - and it’s not going so well! We were just saying that maybe he should have stuck with the online format. 
This is purely anecdotal info and it really will depend on your particular situation.
@SouthFloridaMom9 UF’s Calc 2 is a major pain, it will get much easier when he gets into Calc 3.
On-line is better than large lecture halls. At least you can replay the lecture. Small (30 or less) classes are better than on-line, since they tend to be much more interactive. Either way follow the above advice and form a study group. 
Good Luck!
I agree with eyemgh.
Generally speaking, if the classroom is small (i.e. less than 20 students), it might be advantageous to take the class in person as the TA/prof will be able to get a better feel of any weaknesses students have and make adjustments to lecture accordingly. Larger lecture hall classes, and online classes, won’t have this benefit. The one plus side of online classes is that you can replay portions of the lecture.
IMO, from most preferred to least preferred: 1) Small class in person, 2) Online, 3) large lecture hall
I had a few hundred people in my freshman calc classes, and they were somewhat interactive. (Professor Miller was a great teacher who had taught the dads of some of the students in my class. I still remember laughing when he’d talk about “jolly hand clapper” easy parts of a problem. )