You may want to do a few more kits before jumping straight into all grain brewing. The kit you did was the most basic 'kit and kilo' using prehopped extract. I would recommend doing a few kits that include seperate steeping grains and hops, and then a few 'mini mash' kits that include larger grain bills and less extract. Each step in the kit progressions will make you more familiar with the processes involved in AG and improve your chances for success.
I returned to brewing last year after being away for 30 years. I've made seven different steeping and mini mash kits, including one I made the recipe for myself (a damn fine IPA). Each one taught me something new about my processes, and I'm ready to move into all grain with the brew in a bag method.
Regardless of your path, good luck, tasty beer and welcome back to the asylum....