First, all you did under Customize was enable the Capital Accounts tab. You did not create any capital accounts. Those must be created by clicking the New Capital Account button and entering the member’s/partner’s name and any starting balance as of the day you began using Manager. (Use that feature only if you had a previous accounting system you are carrying over.) Those are also the only two things that can be edited. Read this Guide:
Capital subaccounts are created under Settings. I don’t know what you mean by “it gives option of only paid in advance or to pay.” What are you referring to?
The default subaccount options are automatically linked to capital accounts. They are duplicated for each new capital account created. You can rename them by editing. You can delete them. You can add others.