You will see from the regulations that you must take at least 45 credits from option lists and at least 22.5 credits must be from List A (physics modules). If you are happy taking only physics modules, the normal approach would be to register for all of them (52.5 credits). You could drop a 7.5 credit module at the end if you did not want to go overload.
If you want to take outside options (List B modules or unusual options), you will need to decide whether you want to take them partly as an overload or wholly in place of physics modules. When deciding which physics modules to take, the following may be helpful.
Computational Physics is a skills module. Computing and programming are valuable skills both within physics and beyond. We recommend that all students take their computing skills as far as possible, and at least start this computing module.
If you are interested in astrophysics, the two modules The Solar System and Stars are part of a stream of astrophysics modules. You will be allowed to take later year modules in the stream if you haven't taken both these second year modules, in which case you would be advised to go through some of the material covered in these two modules in private study.
Finally, we have two modules which look at interdisciplinary aspects of physics. They show how physics is relevant to the physics of the earth (Geophysics) and issues around energy (Physics of Electrical Power Generation).