Didn't really have any problems when I started; I did my homework before getting into rebuilding because it was the only way I was going to learn, none of my friends were into rebuildables yet. My builds were always good, but they sure as hell got better and better every time as I learned more.
Just make sure you research what you will need for what you're going to build, especially when it comes to tools. Make sure you have cutters, something to wrap on (those coil master/kuro coilers are really nice to have no, but not necessary if you have patience), ceramic tip tweezers, butane torch to heat and set coil(if contact coil, but not necessary as you can pulse fire on mod to set), meter for resistance, screw driver (i recommend a nice set with plenty of variety in sizes/styles of bits).
Watch plenty of videos on youtube seeing different builds of what you plan to build and try practicing wrapping with single strands of wire from stranded wire (i'm talking just regular wire, so that way you're not wasting any kanthal if you mess up). Once you feel confident, go for the real deal and just rememer ECF is here to help if needed.