A comprehensive minimalist guide on adventurous travel to help you get started on the right foot
There are two ways to go. Either you prepare your touring bike at home which makes sense if you want to start cycling from home or if you have loads of money to spend on panniers (panniers are f*cking expensive!). Or you fly to your departure country, buy a bicycle there and prepare it for touring. There is nothing really complicated in the first way, you just have to choose a bike that you like and mount it with panniers. Keep in mind that touring bikes are especially designed for mounting panniers and there is enough space between the pedal and the rear panniers so that when you pedal the back of your foot doesn't hit the panniers which might not be the case with a mountain bike for example! Though it's totally possible to travel with a MTB. The second way is more challenging and adventurous as you can't predict how easy it will be to secure a bike. It takes a little time to do research and you might scout bike shops for brand new touring bike. However in my opinion the best option is to figure out what is the most popular local sell & buy website and look for a second-hand touring bike there. You could look for these kind of bikes as they are all solid bikes for 2000$ or under when new: Trek 520, Santos Travelmaster, Thron Sherpa, Surly Long Haul Trucker, Fahrrad Manufaktur TX-400, Ridgeback Panorama. These are long distance touring bikes with a frame in iron that is not likely to break and a lot of spokes to make your wheels more robust. You can go 20'000 km with a Surly Long Haul Trucker without breaking a wheel for example.
On wheel size, there is a whole debate on the topic but in my opinion it doesn't really matter. The only thing that I can tell you is that it was sometimes really hard to find spare tubes for my 700x32c tires (like for example in Nicaragua or Colombia). On tire width, 32c was fine to ride all the way from Mexico to Colombia. However I felt like I would have preferred a wider tire at least on the back wheel. And most importantly 32 was not a standard size so it made it harder to find tubes again. Figuring out what kind of tubes they sell in stores and going with that size is a much smarter strategy. On gears, what matters is how low your lowest gears is and that is really important if you plan cycling very hilly areas like South of Mexico. Once again pack light!
For sleeping you can choose between a tent or a hammock depending on where you plan to tour. Sleeping in my hammock in Latin America was fine as there were plenty of trees for example. You don't need cooking gears as you can find food on the road almost everywhere in the world. But cooking is fun and helps you to save money sometimes. If you camp outside, stealth camping is the way to go. It's better if nobody knows where you are sleeping as they won't be tempted to rob you. Take your time to pick a good spot before the night starts to fall. Another great way to meet locals and get a shower is Warmshowers - equivalent of Couchsurfing except it's for cyclists.