Hello - need advice

hello everyone brought a old caravan two weeks ago so its in need of tlc,  havent a clue what am doing, as am a newby,  but ive found it really hard to find anywhere that repalces the sofa cushions,  for less than £2000,  am finding its cheaper to rip it out ans put new carpet down and free standing sofa from Nabru,  is there any reasonable places about ive just not found them,

also can you use normal carpet?  can you use stick and go tiles on the walls in the kichen ?? any other advise welcome xx