Conservatory wood rot

30 year old wooden conservatory is nearing end of life and I'm hoping can be repaired as reasonably cheap as possible. I am no expert but It looks like wood rot around the bottom edges, especially at the door entrance and panel beside. Most windows need refitted (I think) the door is sticking and the structure sometimes feels like it wobbles when opening/closing. These are the main areas of obvious concern although I expect there is probably more once inspected professionally. But can anyone tell me if it could be done "DIY" with special fillers etc if I can post pictures for a better look. Also is there a rough estimate to how much it would cost.