Not closing a deal in the first few months of practice is very common. Being an agent that makes their full living income on RE sales (not investments) is definitely a full time endeavor if you really want to do it correctly. It's full time all day everyday marketing at first until you gain repeat clientele, which for most takes several years. I'm not discouraging you, just giving you the reality.
If you are serious, you should look into some of the big box brokerages that offer mentoring and training for new agents. I won't mention brokerage names, but one in particular (who I hate because their agent's tend to be inexperienced and awful to work with, so I won't say which one hehehe) offers regular seminars and training for new agents that is meant to get you going with a wide variety of marketing strategies. They may require full time commitment, I don't know, but check into that obviously. Also, the larger the brokerage, the better the phone time. Ask for phone time if you can get it - when a random new buyer calls in you'll get the call. The leads are weak as hell, but they are leads!
Marketing to FSBOs and and expired listings is not a good use of your time in my opinion. I also don't like door knocking but I guess it depends on your market/area. I tend to stay away from anything that annoys people, like cold calls and cold door knocks. When a salesperson calls me or knocks on my door, I always say no thanks and close the door or hang up the phone, EVEN IF I am currently considering buying the thing they are selling! Why? Because I don't like getting annoyed by marketing, and I imagine most people don't either. I literally shoo salespersons away as a principle. When I'm ready to shop for an agent, I'll do my research and contact them when I'm ready. Just keep that in mind when you are thinking about effective marketing strategies - be known as an agent to everyone you know and meet. Hand out lots of cards.
Good luck!