Though i haven't yet worked on Freelancer.com, i have been working for more than 10 years as a Web Developer.
I currently manage two cPanel-based VPSs for another client of mine, and was responsible for migrating or setting up more than 40 WordPress-based sites. This included adjusting nameserver settings (to point the domains), and securing each site.
I can advise you on the best plugins for each purpose. I have already worked with plugins such as: Sucuri and Wordfence (security); UpdraftPlus and Backupbuddy (backups); Contact Form 7, Gravity Forms, WPForms, and Ninja Forms (forms); etc, etc.
Furthermore, i am very quick and responsive. My feedback score on another very popular freelancing platform is a solid 5 stars, with more than 80 jobs and 2600 hours of work completed.