The 10 amp (non fused) connection on your multimeter is for measuring DC amperage over a short time span 10-15 sec's max , never for AC amperage, for that you need a clamp meter.
As for needing an electrician it's like needing a trained pilot in a plane , follow the instructions and have 2-3 hrs on a simulator and away you go , electrical work is covered by laws and legal requirements to protect not only you but anyone who comes after you in an attempt to stop as many as possible deaths by electrution , end of story.
If in doubt ask your local authority if you are or are not allowed to carry out said work or do you need a licenced person?
Rgds