Balance sheet

how can I set up the accounting details for the company from the balance sheet of 2017??

do I need to start the whole business details from the beginning?

Manager does not force the user to start over again for every financial year.
you just change the reporting period and if needed set a lock date to prevent changes to your previous records.
read below guides.
https://guides.manager.io/5490
https://guides.manager.io/5510

if your migrating from another accounting software, read the guides section on setting starting balances.

Read this Guide on entering starting balances when migrating from a previous accounting system: https://guides.manager.io/15718.