Does not rule out the possibility that colleagues or superiors will take lunch on the first day of work. Maybe just to get acquainted, or explain the company’s vision and mission. When the offer arrives, try not to reject it. It is important to show that you are ready to chat with your new team. So keep your lunch for another day. Additionally, take a look at myonlinejobcentre.co.uk/jobcentre-plus-national-insurance-number/job-centre-online to look for many jobs in the UK.
Furthermore, what is no less important to do when you first enter work is to ask. However, make sure the question is asked in the right time and really needs to be asked.
In general, you try to show curiosity and desire to learn. Don’t ask too many questions on the first day too. You have plenty of time to learn your work.
Nevertheless, don’t ignore the important questions as well. This is necessary so you won’t cause too many troubles in your early days at your new place of work.