Need help with 13x13 and 19x19 boards

So like the name says I require help with both 13x13 and 19x19 boards. Up to this point i’ve only really played 9x9 and have no clue how to play the other boards, I always seem to miss things and et the majority of my groups killed any help would be nice.

Thank you for your prompt reply and all the references, this should help me quite a lot.

this lecture is also pretty handy. it is a pretty structured overview of the fundamentals. https://www.youtube.com/watch?v=GvB5Yns4JwY