Vauxhall Astra car cutting out and knocking nose when pulling away.

I've got two faults which aren't related.

The first problem is the car makes a single knock noise which sounds like it's coming from the drivers side middle. It's only when pulling away from stationery. Don't hear it any other time.

The second problem is the car has cut out when driving on a motorway, managed to pull over and it started up fine. Today on the motorway again, it felt like the car tried to cut out a slight judder when moving but not cut out and no warning lights on the dash. But 2 weeks before this my car wouldn't start at all, I would turn the key and hear a single click noise and F appear where it displays the range/mpg, got a mobile mechanic out who cleared a list of codes and it started up with no problem at all.

I've done the pedal test and that shows no ecn faults.