I KNOW TO Exercise but muscles?

Just about every morning my dogs whining at me for her walk ever since my mom took her once time so i counted to go to give me a bit some time out the house and plus right now I can't ford to go the gym so here I'm weight 106 pounds but most the time i again couple pounds sometimes when I go to New Jersey visiting my family and few close friends where grew up from moving to Arizona and I go for the summer of a month and we eat all good food so when i come home to Arizona I end up being 116 pounds every Summer when i come back home and I'm okay with my weight but i want to turn into muscles, I KNOW TO Exercise IF so what do i need to do to started doing at home? Is mostly just sit up and push up that i need to do if so by how many times a day i can do at home?

Walking your dog will definitely help.
My friend asked me to look after his dog while he went 2 week vacation, so I would go in the morning take the dog for walk and feed it when we came back, lunchtime I would take it for a short walk, and evening I would take it for a long walk in the park.
After 2 weeks I was shocked to find I had lost 8 pounds in weight and walking the dog was all that I did differently.

Fat doesn't turn into muscle. Fat is fat.