Need your help please!

Hello guys!

I’m a beginner and I don’t know much about website designs. However, I am looking to create a private website for my employee’s to use/log into and communicate with each other and click on links that will take them to google forms. The website that I have in mind/want to create is more an aid in helping my company manage our projects, access forms, create charts, able to discuss topics and only for employees. I want the front page to be a log-in page and only those with user names and passwords can access the site (I don’t want others creating accounts and have access to the site). Would you all please help me with any advice that you may have or any theme that you think already has all of these functionality’s. Thank you all very much and I look forward to hearing your advice!