Mountain bikers.....
There is loads of fitting advice available for free on the net, or from your local library, and far more consensus exists regarding road bike fit than for mountain bike fit...
...and that's why bike fitting is considered by some to be a waste; you are paying out for someones opinion plus a series of well documented measurements, plus as noted above; bike fit is a dynamic thing. It changes as you change over time.
Do things in order;
1. Set your saddle height.
Stand against a wall in underpants and socks, push a book up into your crotch as if you were sitting on your bikes top tube, then get someone to measure the distance from the book to the floor.
This is your cycling inseam measurement.
Then multiply this by 0.885.
Then use this figure to set your saddle height FROM THE CENTRE OF THE BB TO the saddle top.
2. Saddle setback.
If you are tall, push the saddle backwards past it's mid point on the seatpost; you can fanny about with this later.
Sort these two things out first, then try to LEAVE THEM ALONE.
3. Put your bars as high as you can; the aim is to get them down as you get used to riding.
4. Stem length; When in the hoods, the front axle should be obscured from view by the handle bars, choose stem length accordingly.
That's about it, apart from tweaking things bit by bit.
You've got sore hands and neck and arms because you have too much weight on your hands, because you have shuffled your saddle forwards to compensate for being weak. Put it back.