
For more information on each of these vacancies and to apply, you need this website, which is the national one. https://www.gov.uk/apply-apprenticeship
There are other ways to find apprenticeships too. For example the construction industry (from trades to technical) have their own separate website http://www.citb.co.uk/bconstructive/
When you want to apply, make your application the best it can be. Give yourself time, ask for help, and get someone you trust to run through it before you submit it. There is often huge competition for these jobs, but that's because they are worth it! Ask for help and advice.
Then when you are offered an interview, do plenty of preparation beforehand (again, ask for some help and there are lots of interview tips online).
Apprenticeships are advertised all year round as vacancies become available. Jobs starting from July onwards might be advertised any time, but particularly from about April onwards - be ready to apply by preparing a draft application which you can customise when you spot the perfect vacancy. Every vacancy is different, depending on the employer.