I would first focus on getting a LD or two a month once you understand the theory behind it, then raise your goals to one a week,etc. until you are comfortable with continuing. Sure, dreams can be very realistic, it depends how much attention you like to give to detail. Most beginners only have very short LDs (mere seconds or minutes) and learn how to control them as they progress, and eventually having longer dreams (maybe 15-30 mins to even longer). Once you start LDing on a consistent basis, you will see what I mean.