Safari tabs replace existing tabs instead of adding new

I am relatively new to Apple products, 2 years and I love the iPhone, iPad and Apple Watch. I just got a new MacBook Air and I noticed that when Safari opens tabs it will only open 4 tabs. Everyone says that it can open 500, but that is not my experience. I dont wanna open 500 but would like more than 4. If I click on a link in my favorites bar and I have 4 open it just replaces the 4th one with the new site I just opened up. How do I have it add to the tabs not replace the 4th tab? Please be detailed in your response this my first MacBook, so what you say will not translate unless you are specific of where to go and what to do. Thank you.

Rob