Just play! Starting in the middle is generally easier I find. What’re you using to tension it? Looks like a Gibbon type with a ratchet – as I progressed I found the ratchet really annoying, so I ended up with a skinnier line that I can tension just using karabiners – I could feel the ratchet making the line move oddly.
From the pic, the best tip I could give is to look up! I always try to find a spot on the far tree and focus on that, looking at your feet makes it harder to balance. Once you can walk the full length, you then need to learn to turn around (really hard), walk backwards (less hard) and do tricks. I got to that level, fell off and buggered my foot up and haven’t had it out since 🙁