Every photographer has their preferences but there are some lenses that are so staple to upgrade your portrait game...
50mm f/1.8 "Nifty Fifty"
This lens is perfect when you first start out and in general further in your career! It's a great upgrade from the kit lenses that your camera comes with. It's easy to use and will last you a lifetime. I still have mine from about 8 years ago and I still use it often. You can get up close and still have a wide range in the background. I once used this lens on an entire 10 day trip to Japan and took an incredible amount of photos with it. Grab this lens if you're going to do more 1-2 people portraits, food photography and traveling!
This was the first "big" lens purchase that I made and it's just incredible. This lens has more compression, which gives beautiful bokeh, that "blurry background" goodness. This is great for close up portraits like headshots and close up couple portraits.
I invested in this lens when I started taking on more events and knew it was just necessary. It's perfect for events, landscapes, and AMAZING for weddings because of the range. You can keep it on your camera body and use it for family photos, portraits, first dance, ceremony and perfect for receptions so you can zoom in and out on a tight dance floor. Highly recommend if you're doing more of what I mentioned!
I know a lot of photographers love this lens and personally it's not my favorite just because I like my 50 and my 85 but this is great for full body portraits, landscapes and fashion photography!