I'm new to this, but I asked this question to a few different quarters and they all came back the same.
'It depends'.... which i have on good authority is an excellent answer to any medical question
Your endo or GP should give you goals. And those goals will depend on what type you are, how fit you are, how severe your diabetes is, what method of control you are using, how blue the sky is today.... etc
My before meals target is 7mmol/L (126mg/dL) or less. My after meals is 9mmol/L (162mg/dL).