While the UK was part of the EU it was easier and cheaper for employers to import foreign labour to fill vacancies. It makes no difference how many thousands of job vacancies there are if U.K. workers are not trained to do them.
All people claiming unemployment benefits of a working age should be offered places in training schemes to learn new skills or update skills they already have.
To make work pay the minimum wage needs to be raised to a level that people can live on, at the moment we have a crazy system were workers receive benefits paid by tax payers because they are not receiving enough wages from employers.
Also zero hour contracts and bogus self employment in the so called gig economy scrapped to prevent more young people from being exploited.
None of this will happen while we have a Tory government in power.