10reps max will do.

When you reach advance stage, you can go for max 15reps.

If you are able to do more than 10reps, that means your effort level is too easy. You need to increase more weights.

The first 2 months, you will go through hell because your body haven't get used to it yet. Once you get used to all the pain and soreness, then you will start to realize your body getting more flexible. Cracking joint sound is pretty normal, don't worry much.

What do you have now daily? Post it here.