learning support and resistances

hi,
this morning I made a post about learning about resistance and supports. and now looking back at what has happened today. the price went up and hit resistance at almost 9700 and went down got held by support at 9300 but couldn't break through the resistance and also couldn't hold its support so it went down to a previous resistance turned to support at 9080.
so my questions here are:
why does a previous resistance become support and does that make the support stronger for some reason? (see the red circle)
do support and resistance often switch with one and another or is that something to look out for?
are my trend lines drawn correctly? if not how do I draw them?
and lastly, I think the price will go to the 9300 range and if that fails it will go back down to the 9200 range but if it makes it through that range it wil go to test the 9600 range is that a realistic way of reading this chart or do i have it all wrong?
edit: also how are supports and resistances formed and why are they in the spots that they are.