In a school science department, the teachers will give you orders for the practical equipment they need for lessons in the coming week (or maybe even later that day). Your job is to get out the equipment and lay it out. Afterwards, to put it away again.
In addition to day-to-day work like this, you will have to make sure that the equipment is well-maintained, eg batteries are still okay.
Depending on the teachers, you may be asked occasionally to help out with practicals in lessons.
When teachers ask for equipment, they might not give you very good instructions, so you should try to anticipate their needs. If the give you an experiment from a new course, you may not have the equipment in school, so you would work with the teacher to work out alternatives.
If the teacher is trying out a new experiment before unleashing it on the class, you should be on hand to help out.
You would be expected to be handy with the school computer network, so that you can find the resources needed for each experiment, eg download worksheets and exam papers. You may be asked to do photcopying, prepare exam papers and display work. You may need to liaise with other support staff in the school, eg maintenance and IT tech on behalf of your department.
As a physics technician, you won't need to make up solutions, agar plates, feed fish etc, but you should be aware of what your colleagues do as they may need your help from time to time. You won't do as much ordering of consumables. You will work closely with the other technicians as it is likely that you will have to share some equipment, eg power packs.