Just to make you feel better this was my very first attempt at garterlac. I almost gave up on it in the middle but I took a picture of it half done to post here and get some help from the more experienced knitters on this forum. I ended up not needing the forum's help because I just looked at the photo a second time and realized by myself where I was in this puzzle.
Yes, the first one might be difficult. Try doing a mini sample first and if possible have someone next to you for help. I only had the Internet and I managed - just!