i want to start home studio | Help Needed

  Hello Guys, How r u...! i want to start home recording studio for rock songs ...! i just recorded a rock songs. but i don't know which equipments i need ? i have a semi-acoustic + Electric Guitar. please give me complete guaid ...! & also tell me what is audio interface & which is the uses ...! i'm using Sonar Producer 8.5 i'm very thankfull to You...!