It depends on your department. My department don't have any strict rules about any of those things, and I don't plan on starting any. I don't wear makeup but I do know that by the end of a hectic, busy call, any makeup would be sweated off. I have long hair, and though I like to leave it down and styled, it NEVER stays that way. By the middle of a call, it is driving me nuts, or I am so sweaty and hot that I can't stand it. So I normally wear it in a ponytail with a visor. I wear earrings, and my nose is pierced, I have never had any complaints from co-workers, or patients about my facial jewelery or tattoos. Of course being obnoxious with any of those things isn't good.
There is of course a safety aspect with some of these things. Long hair is very easy for a combative patient to grab and cause alot of damage. If it's really long you run the risk of it falling into the patients face or open wounds, or contaminating an IV site ect. Necklaces can also be grabbed by patients. I don't see any issues with wanting to look nice/cute. As someone else mentioned, I don't think you male coworkers will think you are a "sissy" for looking that way, but if they do it will be fun to show them that you can look good and work hard! But, you may have to deal with flirting, and gawkers, from coworkers and patients! I would bet after a few crazy shifts, you will arrive with hair tied back and very little makeup.