FEMALE attempting mechanical repairs

I have a 1999 Chevy Tahoe 5.7 V8 4X4 that I bought
last week. Single mother souly supporting four children
and taking care of my mother. When I bought the truck
I couldn't get it to move. Had it towed. Simple fix from
my thought. I got under it and manually took the tcase
outta natural. The last owner took off the actuator
believing that was the problem. Well yesterday I got
stranded on the side of the road. I have no help. The
suv runs. It revs up, won't move. Sounds like it's
shifting. I don't think tranny. But I'm about to climb
under it and service the tranny myself. Hard to find
both time and money to do this. I'm about to check the
cables on the ddriver's side of the tranny. I also
replaced the linkage that was severed last week. I'm
running some asshoas whole just intentionally
climbed under my truck and drained the tcase of fluid.
Find it funny the drain bolt is so clean. Hrmm. But I'm
seeking a little help if any of yall wanna help a woman
out. I am slightly mechanically inclined. I set on my old
truck a chevy Cheyenne and was there ten hours
replacing value guide seals. Fun stuff. I'm praying it's
simple seeings I'm a simple woman but my link isn't
goin that way lately. 27 with allot more to learn. So
please teach me. Thanks! -Mandy