New here want some help

Hey so im new to this site and to mtb all together. I come from the bmx world a few years back and now im 22 years old and want to get into this hobby. Maybe get a bike for me and the girlfriend. I gotta say holy shit! These bikes are crazy expensive. I know you get what you pay for but i dont have thousands to drop on a bike right now. Im wanting to get back into shape and do it with something im going to enjoy. So i said a bike is where my heart is so here i am. I was wanting to know is their a kinda budget bike i could get that wont break the bank. I absolutly love the look of a 29er and would love to have one. Another thing i love is the downhill forks. They make it look like a bad ass dirtbike and very aggressive. I know im not gonna get everything i want off the bat, but would like to get something with a good frame to build onto as time goes. What are your suggestions? Im a rather large guy around 6'3" 250ish right now trying yo get back to 200 before it warms up here in michigan. I dont intend to go super crazy with this hobby as in huge drops and crazy trails. Just something that has a few jumps and also ways around them for the girlfriend she will never jump lol. So please help guys! Thanks in advance!