No - go for an electrician.
The thing is the job you want to do - installing external cables, deciding whether to export the earth, installing a CU, designing, installing and testing all the final circuits, etc, is not a trivial job, and I can assure you that it involves knowing far more than you think it does.
Asking questions here can be a useful part of a learning process, but they are not a substitute for proper structured studying. The key term there is "learning process" - you cannot learn all the things you need to know just by asking questions here. It isn't structured enough - it won't provide you with a way to progress where each step builds on what you learned before.
You can't carry out a job of this magnitude by asking whatever random questions happen to occur to you. You've already shown that you have some dodgy misconceptions - what if you get something wrong because you have no idea your knowledge is wrong? What if you miss something because you simply have no idea it even exists, and just don't realise you don't know it?
