Add Functions In Wordpress Theme

I have jobify theme purchased in themeforest. [login to view URL] all i want to do is to do the following. this is a simple task. if you can deliver this one ill guarantee you that therell be more projects to come. im looking for a long term developer with my company 1. just change my homepage with login screen with Employee and Candidates Button and you need to add a field where the employee and cadidates can put the Vendor Code. 2. I need you to make a function where the candidates and the employer can filter out the jobs by the vendor code 3. putting survey or quiz or personality quiz by the employer to the candidates and show the score shows on the candidates dashboard? and be able to filter out the candidates scores with the employers. (The plugin used here is wp job manager) PLEASE READ THE ATTACHED FILE My Budget Is 7500php I NEED IT DONE TODAY THANKS!