Welcome to the forum!

"Goals: Really to gain about 15-20 lbs of weight (hopefully muscle) without really going to the gym that much if any. I would like to do it by using dumbells and pushups. Some of you may be laughing at me hysterically right now for saying that, but I would love to hear your ideas/comments."

The best way to gain that kind of muscle is to work out in the gym on a regular basis.

I'm not being sarcastic, but everybody started somewhere. So, I ain't going to laugh at you. The first thing ya got to do is get it your head, and your heart what you want. Don't worry about how little weight you can do, or what anybody thinks about you. I say F*** them. I started out lifting weights at 23, and could barely bench 95 lbs with proper form. But, I had it in my head, and heart what I wanted to look like. I'm sure some of the experienced lifters were laughing at me. But, I tuned everybody out, and focused on lifting. I've put on over 100 lbs since then.

The bottom line is make up your mind what you want to do. Then train smart, and eat right. You WILL achieve your goal by doing this.

Good luck! Don't hesitate to ask any questions either. A dumb question, is one that's not asked. There is a lot of experience here!