I have been using blender nearly 7 years (ever since 2.31a) and when i first opened it i got scared and didn’t open it for a week then i did the old quickstart and model/texture a castle tuts and i was going great and in those days there was no wiki or anything and tuts were few and far between so it took about a month for me to get around in it, but in this day and age of blender i would say 1-2 weeks you will start getting decent and will know your way around