1982 2001 Stringers…No turning back now.

Hoping I can get some direction as am feeling may have bitten off more then I can chew. Had the soft spots up front and continuously saw wood shavings. Started by ripping up the carpet and seeing the soaked and rotten wood. Stringers almost non existent in some parts. Worried am not going to have any kind of template to work with. Am trying to figure out how to post some pictures. As you can see, used cutting tool on edges in front. Also worried about what I need to do with jagged edges and how I put new floor in, or do those edges need to come out (Do not want to cut through hull. I have read of Coosca? Instead of wood? Where do you get? Is it worth it? Do you use it for the framing beyond the stringers? Are there blue prints to just create a new stringer? Clearly a lot of questions here and any and all direction is much appreciated. Love this 1982 Nautique 2001 and hope to teach the grand kids how to ski on it. Very intimidated at the work ahead and want to do this correct. Thanks in advance.