Need to build new forum on existing website.

We have a search directory website Like coursefinder. Co. Uk Its written in PHP and uses mysql database Training institutes self register using a sign up link and training center data stored in institute table And private tutors also register them self using sign up link and this tutors data stored in separate tables called as tutor table. Website visitor who is searching for best training institutes search using search button and if learners want to send messages to institutions or tutors they use send message button then it will ask fir email and other details of a learner then this information will be stored in the separate dB table called as learner table. We have article section in the website also which uses WordPress and it has separate dB. Now we need a forum section in our website which should use new dB or existing word press dB or existing main dB. Forum can be built existing WordPress installation or write new code in PHP. Forum should have these basic functions Post a question Answer a question All questions and answers shoukd be approved by admin. Question and answers shoukd have a specific length restriction. To post or answer he has to sign in or signup Sign up is either institute link or tutor link or learner link As if now there is no sign up link fir learner, you need to create new. When clicked on post a question it should open a pop-up with signin, and with sign up link. The sign up should have 3 options (institutes or tutor or learners) Refer Urbanpro ask and answer link. Most of the time institutes answer the question. Around 6000 institutes already signed up for our website. So you need to use the existing dB for authentication. The url should be same as quora. Com url structure. The website running on Linux aws machine. You shoukd know the git on how to pull and push the changes. We test the code in test server 1st then implement the same code in production. There is no cpanel. Don't ask for production access.