How do I start book keeping for a new company?

Hello Userlaxmi-sivasubram, 

Welcome to the Community page, 

To start bookkeeping for a new company you will need to take out a new account product with Quickbooks then use that for the new company. This link will show you the different products we have on offer in Quickbooks 

@userlaxmi-sivasubram 

If you are the bookkeeper of your own company, just open a new QBO account.

https://quickbooks.grsm.io/UK

If you are the bookkeeper for your clients, you may ask the client to open a new account and you may utilize the QBO Accountant account to manage them.