As long as you don't crank on the trussrod and instead just use small incremental changes, like maybe 20 degrees of swing for each adjustment and then recheck, you should be OK trying it yourself.
There's nothing quite like learning by doing.
Everybody has a first time.
It's not rocket science but you do have to understand what you are doing and what actually happens when you do it and why you do it.
The first setup step is to check the relief and adjust if necessary.
If someone reading this doesn't know what neck relief is they need to read up on it.
Also read up on how to check neck relief.
Adjusting it is as easy as swinging a wrench a small amount.
Knowing how to measure the amount of relief you have is key.
Relief is related to string gauge so if you are thinking of switching gauges, now would be the time to do it; before you set the relief.
Tuning to pitch and the gauge of the strings combine together to affect string tension on the neck which affects neck relief.
Relief is required to allow the strings room to move as they vibrate and as such it really isn't the sort of thing that is subject to a lot of personal preference.
There needs to be a certain amount of relief for the guitar to be playable.
Too much and too little both present issues.
AFTER you have ensured the relief is appropriate, then you can address the action height.
Saddle height, as mentioned by a few others already, dictates action height and it is more open to variations due to personal preference ... within reason.
If you tend to switch back and forth between standard tuning and altered tunings you'll want to set the action a tad on the high side when using standard tuning.
The majority of altered tunings involve detuning which will reduce relief as well as action height.
Be careful that you don't set your action too low.
If it is too low the strings will contact the frets and create problems.
The guitar will buzz, it will lose volume and sustain, it will make your guitar tend to 'fret out' and the worst part is, it will make your guitar sound like a cheap piece of garbage.
No amount of buzzing is acceptable.
Acquiring a softer feel by sacrificing tone, volume and clarity and creating buzz is a silly thing to do on an acoustic guitar.
The other downside to going too low is that you usually have to get a new saddle and start again from scratch.
I believe somebody already said that as well.