I wanna start doing basic exercises like crunches, leg raises, squats, and pushups.. how many times a week should i do it? and how many sets of each shall I do? I just wanna tone my body a bit (make it look smaller than it is). Thanks.

As a fellow exercise enthusiast like you I have to ask you one question, are you wanting to build muscle or lose fat? You can't say both even though it is technically possible I for right now want to know what is your goal, so far you seem to want to gain some muscle so if so then do just what you're doing but if it's weight lose then do cardio or HIIT.