Hey lovely! There are tons of comments in here, but I wanted to throw in my own tips, as a cis woman who felt like she missed the lessons everyone else had as a kid, and decided to figure out femininity around age 29.
Like others have said: You are a woman, so everything else is up to you. There's no right way to do this. Play with different styles and see what you like!
I rarely carry purses, but when I do, I have one black satchel, and one camel bucket bag that I switch between depending on the season and outfit. "What's in my bag" videos on YouTube will give you an idea of different bag styles, and different items you might want to consider carrying with you. My purses are generally higher quality that I purchase from designer outlets, and my work bags are all from Target, because they get beat up so often.
The tampon thing isn't common enough to worry about, and if you do get asked, no one would be caught off guard or upset if you told them you don't have any.
Makeup is hard at first, and practice is the only thing that helps. I recommend YouTube tutorials (particularly Lisa Aldridge - she's a professional makeup artist, and she doesn't go crazy like so many other makeup gurus. Her style focuses on highlighting your own beauty, not covering it with 47 products).
It can be intimidating to get into makeup, because the stuff isn't cheap, but there are drugstore dupes that allow you to play around without wasting money. The CoverGirl truNaked palettes are a good beginner eyeshadow, as well as Maybelline matte ink lipstick. I think it's worth splurging on a foundation that I love, but your skin is flawless, so you may not need it at all!
As for fashion, Pinterest is your friend. Make a board of outfits you love, and styles you want to try. I promise a pattern will start to emerge, and then you have an idea of where to start!
Without a full body shot, it's hard to advise on what would suit your body type, but the key is this: do whatever makes you feel good. Some women look great in jean jackets, but I feel boxy in them, so I don't wear them. If you feel confident in it, and/or feel comfortable in it, then it's perfect.
Other random tips: mascara, eyeliner, and a little highlighter on the cheekbones is a good 5-minute routine that's not too much fuss. Stiletto heels are rarely worth the pain and effort. Wear sunscreen everyday, no matter the weather. And in the words of Coco Chanel, “Before you leave the house, look in the mirror and take one thing off.” Understated beauty is so much better than trying too hard.
Good luck! Keep asking questions, and have fun finding out who you are!