If your user account doesn't have access to the members section you can't grant access to anyone else.
If you don't have access to the members section, chances are that whoever set up your admin account didn't check a box to allow you access to it. Not every site uses the members section anyway. Users get logins to do the content editing, but members are usually outsiders who are registering for newsletters and such-like.
Does your website have members? If not then its probably fine. Run a query against the umbraco database of:
select * from dbo.cmsMember
If it doesn't return anything then there are no members.