Modern Vespa

I bought a 2019 Vespa Primavera Touring and am replacing the throttle cable, the part I have received from Vespa included the grip and throttle all attached so i am replacing the whole thing.

I have all the plastics off and have access to where I need but my question is this. Do I put the grip end on the handles first or do I put the throttle cable into the carburator first?

Also, on my left brake, I get very little resistance until I close the brake a far distance, Is there any sort of cable anywhere on the scooter that I can tighten that will allow me to have more immediate resistance on the brake.

I am going to attach a photo of the scooter for reference.
Thanks guys!

I always start at the handlebar throttle assembly and then work my way back to the carb.

ensure everything works properly before putting the grip onto the throttle tube and make sure to lube everything well.

left brake lever is the rear and is cable operated, it probably just needs adjustment.

Ok thank you