As far as I understood there is nothing like "help" with that. Either you "manage" to do it right in that mission - or you don't. Concerning the fact that most of the "The Crew" players seem to be hardcore gamers with slippy nippy fingers - which I'm NOT - I sometimes feel like a noob when getting comments like "I find it bizarre that ..." (although having no problem with pure racing games like "Dirt Rally" or "Project Cars", or the tests like "speedrun", "slalom" or "jump" in "The Crew").
Okay, just uninstalled 'The Crew' without trying the first Calling All Units mission again. Since the impression was too bad after leaving a stuck mission be for a while and thinking a bit about it. Guess the story missions would get more difficult and not easier in that game, and when I have already problems in this early mission this might be the wrong game for me. Had even a bad experience of 'The Crew 2' after two free play weekends, so now the genre 'The Crew' is definitely dead for me, would better spend my money on 'Dirt Rally 2'. Only UPlay bound Ubisoft racing game I still have installed is 'Driver San Francisco' which as an older game has limited support for current PC Wheels.
Not the first Ubisoft game I uninstalled, 'The Crew' now meets my UPlay uninstalled games 'Splinter Cell Blacklist' and 'Heroes VII', and actually playing Ubisofts 'Tom Clancy's The Division 2' as singleplayer I start to loose interest in the 'The Division' genre too, since that one is more and more orienting towards the hardcore/power players and less on the shooter middle class.