No, D&D isn’t difficult to learn. Once you get the idea of how the game is played, you will play with friends for hours on end.
Note that the learning curve can be a challenge to some, but as long as you refer to a few reference books by your side, you should be grinding your way to becoming proficient in playing the game.
However, it is also worth noting that Dungeons and Dragons becoming a master in D&D and becoming extremely proficient will take you a lot of time. As you play more D&D games, you will start to learn and understand how the system works and will be able to use all resources in the most efficient ways.
Some would rather play the game, while some are born witty and better off playing as DMs to provide players the best D&D experience.