Total body training two days in a row?

I haven't worked out in years since having my son. Very happy to have just joined a gym and am consistently attending the total body conditioning classes - some are cross training, some are boot camp style, all seem to incorporate cardio and interval training. I use 5 pound weights right now. Typically they ask us to do 3-4 sets of 8-10 reps of upper body work. Lower body work is incorporated through squats, etc. sometimes holding the weights. I am generally tired by the end but am able to complete all reps. Under this scenario, is it okay to work out (attend different classes) two to three days in a row and then rest for one or two days, even if my muscles are slightly sore (no excruciating pain or limited range of movement). I know this is a lot of detail, but haven't seen this specific question answered anywhere on the net and am hoping to get good information so that I can workout with some intelligence, see results and not hurt myself. I'm not looking to get big, just toned and drop some body fat. Thank you for your help!!