Firstly good luck with the practical, I hope it goes well.
Get some practice in beforehand so that you are confident on the tests required.
You will have plenty of time for the inspection and test if you proceed logically.
Get all the installation details (earthing, bonding, tails size,main fuse, main switch, circuit list, etc) down on your sheet first so that you can ensure everything is covered.
Always perform complete safe isolation before starting work on the installation.
Remember that inspection precedes testing and that the installation should be visually and tactilely checked for errors prior to starting testing.
Understand the reasons for testing and the sort of levels of results you would expect so that you can immediately correct if a result is strange.
e.g an R1+R2 of 4.5 ohms, hang on, stop, I am measuring the resistance of copper conductors over reasonably short distances, this should be in the region of tenths of ohms, what is wrong, oh, the crocodile clip has almost slipped off, sorted, carry on.
Periodic inspection should not require too much in the way of dismantling, inaccessible items are not covered by a periodic inspection so you do not need to know if the cable is run correctly in the wall, for example.
Insulation resistance tests should be performed with the cpc still connected to the earth bar so you are testing live and neutral to earth and not to cpc only.
