I've been at this whole thing for about a month. I started out on a different site that went directly into most common power cords before making the jump to GT. Almost everything up to the 5 power packet is pretty new to me. I'm stuggling with the single finger cords and the transitions as well as spider leg excersie. Yet, I can jump up to power cords and keep up with Lisa no problem? I did spend about 3 weeks on another website just playing the 5 power cords and the wealth of 80's and 90s rock songs that I heard through strumming the cords.
All in all, keep progressing through the lesson. The Spider Legs Exercise is not the meat and potatoes of guitar. At least I hope not. It's just an exercise warm up, to prepare your fingers for the task at hand. If you look at the beginner page of lesson, just under guitar fundmentals one, there are 3 extra boxes. Click on the pratices box, on that page you will see exercises, check out stretching video. Add that to your list of things to do every day, and right you sit down to play. Use the Spider Leg Exercise to warm up, as well as your list of notes and cords learned in previous lessons. I don't use the videos every day, sometimes you just have to learn at your own pace. I started making my own drawings of the cords, in the same arrangement of the songs Lisa prepared. And just sitting in my play area, and working on the songs with out a video. If you get bored, change up your strum, instead of strumming each note 8 times, change it to 4. If you want to pratice changing cords, hit each note twice then change. Nothing say's you can't move on to the next lesson and try to add another tool to your bag. When you get frustrated with one set of notes, move forward or back and just change it up for 15 minutes.
My go to is the intro notes to "Nothing Else Matters" by Metallica. All you need is your right hand and its 4 open cords on repeat. It's just a nice, easy, calm melody to play. When I get frustrated with my left hand or my right, I put the pick down, I sit back relax and pick out those cords for a few minutes with my finger. I've been playing that tune for over a month now, that I pretty much end every pratice session with it. No matter, how frustrated or backwards my lesson turned out for the day. Its the one thing I can end my pratice with that sounds exactly like the song.
First 8 seconds of the song is all I know up till the first E cord on the fretboard. I play it over and over again. The link is the complete walk through, however if you fingers get tired and your just flat out frustrated, give the melody a whirl.
https://www.youtube.com/watch?v=7silbMA9UME&list=PLzAbzNpL5avGq9bsR_KU5JrSMXuZbnePO&index=1&t=31s