Musicians Institute has the most excellent Dean Brown showing us advanced guitar techniques. Concepts pop up like Sonority and Tertial Harmony and many more albeit briefly. Leaves you wanting more it does! Several viewing worth of guitar know how are here to glean however! Lesson One is the Rhythmic with Funk, Afro-Cuban and blues strumming and counting techniques which are beyond beginner level. Not too far but beyond. Beyond me anyway, now, but we'll see about that in time.
Are we ready for this or not I ponder? You, dear reader, in my humble opinion, need to assess: Have you been strumming your guitar counting your half notes out loud as you strum? Your quarter notes? Just hitting the downstroke for 4 strums? Then the eight notes where you count both the up and the down and strum on each. Out Loud is key. Makes all the difference if you count out loud! These 'child like' exercises are key. As simple as you can make them. Over and over for ten or twenty minutes every day for at least 6 months. Metronome dutifully clicking away at +- 80, 100, 107, 120 and more bpm. As slow as you can at first to build foundation and you will see improvement 100% guaranteed!
And if you do those and other exercises, you can, and will develop. Growing from someone with undeveloped rhythm to someone with a developing sense of time and rhythm. An inner sense! Engendering an ability and a confidence or at least and inkling of rhythm is easier than you think. I made some progress and was encouraged! I can't believe it really! Those skills may be enough for me to take advantage of the exercises in this guitar lesson if I apply myself further. I think here for these advanced poly-rhythmic exercises we want to get the feel of these beats under our skin and then approximate them as best we can to become familiar before attempting any fancy stuff. Practice makes perfect. Take your time and believe you can!
Just don't give up trying to do what you really want to do. Where there is love and inspiration, I don't think you can go wrong.