Dont worry yourself about the installed circuitry just yet,if its a half decent firm,the spark wil explain/teach/show you what to do
Practical hands on experience will assist you in working most of it out, as you progress
You can use this forum for ongoing questions as you come across things you may want advise on
Using the tools.how to handle a pair of cutters and cable strippers,screwdrivers crimpers etc
Getting used to stripping and connecting accessories will probably be the more useful skill rather than how to wire
You could set yourself tasks at home with sockets.pendants etc, practice in the shed,screw up a pendant with three cables into it ( 3-plate) practice how best to set out the cables,strip the insulation,bare the cores and connect,whilst standing on your head or on a ladder even
Mount a socket pattress and connect and fit that socket,take a look at your home installation and inspect earth bonding, accessories and consumer unit even ( isolate where necessary of course,or you may not survive to start the job
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