Forgive me, but I actually have traveled to Europe and assorted locations in North America and mostly just winged it. It is a really fun way to travel, and generally VERY easy to do, especially - in of all places - Western Europe. To start, you just need a plane ticket. I suppose you could say I researched cheap flights.
These days, one can mostly rely on credit cards and/or ATM's.
In Europe, an easy way to roam is to have a Eurail Pass. They sell assorted passes, but a popular one is the 10trips/2 months pass: 10 train trips within a 2 month window. On top of that, you can reserve a sleeper car (for an upcharge). In years past you only needed to make overnight reservations about 24 hours out. just wherever you feel like going! A quick glance: single= 65-70 Euros, double = 30-40 per person - varies by train. Rental car is also an option, but Europe has some nasty speed camera traps, expensive gas, and pricey tolls.
Other folks do wing-it travel by bike/backpack/hostels. It is also super easy to wing it and get a hotel or hotel room in just about an European city. Many (most?) include a morning beverage and (some type of) breakfast.
In pretty much every city train station/airport it is really easy to stop into a travel office to buy any kind of assorted activity pass you want to buy. So like in Paris, you can buy a 5 day museum pass that is good for unlimited entry to like the top 50 Paris museums. Or if you want to tour the Loire Valley, you just get a pass good for assorted combos of 3 or more chateaus, sold at the entrance of every chateau.
Being able to access wifi is helpful. Hotel staff are often very helpful if you have any questions about where to go or what to see, but usually the main things to visit are rather obvious. If one's hotel has a concierge, they are awesome! Just off the top of their heads, they often know the best discount deals and all. It is really fun to just arrive some place and wander around. Maybe do a little shopping, maybe visit a park, some cathedrals, landmarks...
You also don't need to make any major plans to eat for the most part either. Cities and smaller towns usually have plenty of options in assorted price ranges, and menus are usually posted out front. If that's too hard, Europe has plenty of fast food places. France alone has nearly 1,500 McDonald's, and a French chain called Quick, among many others.
In the USA, it is like super easy to find roadside hotels at almost every highway ext. Many again, include free breakfast. You often get a lower rate if you can call/search ahead, but an hour will do.
If all else fails, ask a local. Usually people are happy to tell you the name of their favorite diner or ice cream shop, or what 's fun to visit.
