Hello Ruby3,
The instalation is normally carried out by Openreach and unless they have improved the system it will need two or three visits because no one person seems to do it all.
There is normally two or three parts to the instalation and each crew does different parts.
By the sound of it they have already checked the nodes in the duct, have agreed with you on a dig route for the cable and you have given them Permission to Dig the the first crew will probably just dig, will fit a cable between your wall and the duct and will make the garden good.
The next crew will fit an exterior junction box on your wall and will connect the cable in that junction box and will connect the cable in the duct/terminal in the road.
Lastly a different person will arrive to splice the fibre cable on the wall of the house to a flexible cable that goes through your wall, (it may need another hole drilling through the wall), and that person will fit an ONT inside your house.
Connect the router, three steady green lights on the ONT and your done.
Obviously it is better if you are there for all visit because you may not like the route of the cable and the position of the external junction box and they need internal access to fit the ONT.
The upside is that FTTP is well worth the hassle and and it should only need to be fitted once albeit spread over three days with delays in between visits.
