I'm more of a lurker than a poster, but I can so relate to your post.
I was completely intimidated by mesh.
I went to an early mesh store that i found completely intimidating and couldn't figure out a single thing to buy and left thinking this obviously isn't for me.
A year and a half later or so, a dear friend of mine got the Maitreya Lara body and showed me her avi with and without, and I immediately went out and got a Maitreya Lara body, and after a learning curve, figured out the HUD and clothing appliers
About 6 months after that she went and got Catwa Catya head, and again, showed me her look before and after..I did a little reading and research...(Mesh Body Addicts and Catwa web pages) and got a Catya head..I loved the head right away, but it was a huge learning curve for me working with the head and the HUDs...I had no idea to look for skin appliers without makeup, so I could add my own...I have a bunch of skins that have makeup on them because I thought the Catwa hud would clear baked on makeup..Of course it didn't...That was just one step of the learning curve...lol...
It all comes together with some patience and finding your look, and asking questions.
There's a lot of knowledge and support for mesh bodies now, and many, many folks are very willing to share their knowledge.
The replies are great here, and it's absolutely best to go around to the places listed, grab demos, save your current worn outfit, and start demo'ing..:)
I recommend joining the group Mesh Body Addicts in world, as a resource if the group support of the head you purchase isn't responding...I find this to be a group of nice folks very willing to help, and of course joining the group of the head you purchase. (If you go with Catwa, Catwa Head Friends has amazing CSR support for all hours except very late SLT/PST nights...But sometimes Catwa Clip is on those hours, and will jump in group to directly answer a question now and then..:) )
I definitely wouldn't let worry about figuring out mesh deter you from purchasing a head, especially if you enjoy finding unique skins and makeups and changing your avi....Mesh heads literally are a game changer for individualizing your avis, and it's so interesting and fun!
Take things slow and have a blast!