A Professional Wordpress Expert Required for W3C Error Updates

General information for the website: We are a marketing agency specialising in the fintech, payments and alternative economy markets.
Description of requirements/features: BRIEF: Our website is run off Wordpress CMS. We require the following:

1) Correction of W3C errors and warnings approx. 90 (majority are small code changes) - we ran our url (www.bluetrain.co.uk) through https://validator.w3.org/ and received a report for errors and warnings. For the full scope of error messages please run our url through the validator link.

2) Re-sizing current images on blog posts (smaller) - approx 5 posts, with the ability upload images to be automatically sized with the same image parameters when we create new posts.

3) Adding Linked In and Twitter Account feeds - plug-ins installed but not fully activated.
Specific technologies required: Wordpress
Extra notes: We need this job turned around quickly, so if you have cannot start immediately please do not quote for job.