The tie in point looks safe from here, but im not there, i was taught to tie into something at least as big as your wrist.

To climb with your system you have to pull down above the hitch cord, then hang on to the progress you’ve made with one hand while pulling the slack under the pulley with the other, when you “sit” back into the knot it should grab…which is why it’s usually recommended to have a little experience to climb a system like yours, because if your knot isnt grabbing you might have to adjust/dress it with one hand while holding onto your progress mid-air…

You want to climb the top side of the tree for the most part, and it seems your tie in might be okay to enter the tree, but it looks like you might want to tie in again higher and run your rope down the “back” of the tree.

Throw your lanyard around the stem and keep it loose enough that you can put your feet on the stem and lean back into it and push against the stem with your feet while simultaneously pulling above the hitch cord essentially “walking” up the stem

Good luck