I have some advice that may help your situation.
1. It's important to try and strike up conversion over topics that you know you can both relate to. For instance, whilst at a public urinal it is beneficial to make eye contact with the person next to you and comment of the state of their "stream". This can also lead in to the both of you discussing possible dietary changes to improve the fluidity of your eliminations.
2. If you're at a McDonald's maybe try making sure they see you snatching their burger. This will ensure that the other person has an incentive to approach and talk to you. Before, you were strangers, now you are connected by the common interest of both wanting the same burger. You can discuss the qualities you most admire in a burger and make sure the other person knows how you admire their taste in burgers. If this happens to be someone you are attracted to, you can even try a line like "I may have stolen your burger but you have stolen my heart, wanna trade and call I even?". The sly wisdom of this line never fails to make the ladies (and gents) swoon.
3. The simplest way to meet people is to go to a place where you know there will be others looking to expand their social network. Like a federal prison. Or the grocery store. Or the DMV.
4. Meetup groups can be good but it often helps to show initiative and maybe start your own group. What sort of things do you like? Since most people like eating/sleeping, starting a group that revolves around watching over people eat/sleep is sure to gather the most interest. Maybe offer to make a video that members can take home with them.
5. When meeting new friends, it is important to stand out from the crowd. Most people are asked how their day is or what they think of the weather time and time again. Maybe walk up to people on the street and throw out a controversial opinion, such as "abortions should really be mandated by the state after the third child". Or you could tell someone in no uncertain terms that holding hands before marriage will lead to eternal hellfire. By skipping the small talk you will allow the other person to speak passionately and open up their deepest beliefs to you, creating a much deeper bond than among normal aquatainces. This is sure to spark a rich and engaging discussion as people love discoursing with others whose believes radically differ from theirs. In fact, it can really cement a friendship if you vehemently disagree with them as much as possible about even the most insignificant of topics.
5. You probably walk by parents of small children every day. You should offer to watch their children so that they can go on a much needed spa day. Providing this service will make them appreciate you, want to be their friend and welcome you into their lives with open arms.
6. Make a list of all the different things you can think of that exist: toilet cleaner, dish soap, serial killer, sexually transmitted disease. Whenever you are stumped for a conversation topic simply ask the nearest person what their favorite one of those things. This is an amazing trick as it allows you to never be stumped for conversation again! If you don't know what to say to someone, ask them their favorite bird. If you don't know how to respond to that because you don't actually know anything about birds, simply follow up by asking about their favorite topic to spread on toast. This may seem like a disjointed way to go about it, but trust me, the conversation will flow as naturally and smoothly as your favorite toast toping.
7. Above all, sense of humor is important in a strong friendship. This is why it's important to make a conscious effort to laugh or joke about anything odd or weird looking about the personal appearance or mannerisms or anyone you meet. Potential friends will be sure to appreciate your attempts at lightening the mood.