Anyone that can give me a good starting workout?

I want a specific work out to start with from there il kinda work up my reps or watever my self. I really don't want to do sit ups tho idk why but when I do it hurts my neck an I get head acts then my tail bone gets bruesed, I just what to build up my upper body. I also have trouble sticking to it becouse I feel like no matter what even if I work out my left arm more my rite one feels more toned an bigger an no it's not cuz I jack off to much lol i need a home wprkout I got some free weights and around Christmas ima get a pull up bar, so yea any motivational tips or just general tips would be helpful to. Also I have trouble eating for some reason like I'm really not hungry an when I do eat I try to eat more to gain weight but it seams like I just get puffer looking for a day or to then I looker more skinny again, I mostly eat fish, patatos, hamburgers, hot dogs , meats Ect and I drink coffee soda and watter sometimes juices I try drinking a couple glasses of milk tho. Last thing tho, when I do my push ups to how can I make sure that I'm using both arms equally, I try pushing with both the hardest I can but my arms don't feel like there getting the same work out. Thanks for reading all that please don't just answer one part of this cuz I know I put alot and Id really aprisheate it.