You can check you savings account by simply going to your bank's website, entering the login details they provided you, going through the security process.. And you should then have full access to your account.
If, at any step of the way, you will like you are missing details or have not been given certain details to gain access to your online savings account balance, then the case is probably that you have not activated or spoken with the bank about being able to activate your online account.
Because each bank is different, it is imperative that you speak to an advisor from the bank about setting up access to your online savings account. Just go into the branch or call them on the phone and ask them!
They will have instructions, leaflets and more help that they can give you.
If you ask anyone on the internet, how are they to know how your specific bank operates? Unless they happen to go to the same bank as you?
And even then, it is not guaranteed that they have a saving account which is accesses in the exact same way as yours, so your best option is truly to communicate with the bank and ask them very simply "how do I check my savings account balance online?"