Temper is a platform for hospitality professionals where supply and demand meet. As freelancer you can find jobs through the platform. When you as a freelancer would like to do other jobs such as for example photography, this is possible of course. Note that all invoices that you have as a freelancer should be accounted for in your declarations.
It can be the case that the current description of your business is not yet in line with the activities that you would like to carry out. Before you can use your VAT number for these new activities, you should add them. To do so, contact the tax authorities and/or the KvK.