To airie, the OP: My advice is the following: Stick with Nikon for a few years...I've shot Nikon since 1982...I bought myself a FULL, 2-body, $10,000 Canon d-slr and lens and flash system a few years ago and used it concurrently with my Nikon system...I SOLD off the Canon system, (580 EX-II flash, 20D, 5D, 50/1.4, 50.1.8, 18-125 Sigma EX,135mm f/2 L, 70-200mm f/2.8 L-IS USM, 24-105mm f/4 L IS-USM, 135 2.8 Soft Focus, 85/1.8 EF, 100mm f/2.8 IF Macro), and kept the better system for me...
ADD a mirrorless system body if you want to, in the future, but do smart research!
Right now, work on learning how to "do" photography! Read some books from the library. Watch some videos on YouTube, but realize that YouTube has a LOT of low-experience noobies making videos about things they JUST only recently learned to do; BOOKS on the other hand, are carefully vetted by publishers, and are written typically by people with vast experience, and are edited by people who understand the field the book is competing in.
Be careful of who you learn from, and be careful of people who give you "good advice".
Just sayin...