-Daytona (24 Hour)
This is a version of the Daytona Superspeedway that includes an infield section and a chicane on the back straight. Corners both left and right.
The cars are multiclass sportscars/GT cars. The fastest class are prototypes or something quite similar to prototypes. For 2022, there should be 5 classes (that I'm aware of). These are GTD Am and Pro (GT3 cars, difference between classes is driver rating), LMP3 (baby prototypes, just faster than GT3), LMP2 (significantly faster than LMP3 and GTD) and the top prototype class (last year this was DPi but there are some regulation changes incoming for the top class).
A 24 hour race with yellow flags/safety cars, startegy and having the car in good condition at the end are key. Tight finishes, especially in the GT class are common.
This is the longest race in the WeatherTech Sportscar Series calendar, with 4 other marque endurance races (Sebring 12 Hour, Watkins Glen 6 Hour & Petit Le Mans which is 10 Hours). Sprint races of under 3 hours are also on the calendar, including a few street circuits.
-Daytona 500
A 500 mile, 200 lap race on a large oval that's flat on the throttle all the way. Yoo do not race the track in this race. The cars are permanently in a pack because the slipstream/draft effect. The goal is to stay with the pack and make your move at the very end. Having many leaders, having team cars group together and work together to get to the front is common. Aero is weird in this setting, unlike any other area of motorsport. There are phenomina like "the big one" that occur in this type of race too, massive crashes that can take out half the field.
-NASCAR Cup series
NASCAR Cup series generally is more difficult to explain. Generally speaking NASCAR races at 5 types of track, those being
Superspeedways (Daytona & Talladega),
Intermediate ovals (ovals longer than a mile that aren't SuperSpeedways),
Short tracks (Bristol, Martinsville, Richmond etc. Tracks shorter than a mile)
Road Courses (Watkins Glen, Road America, generally what most Europeans call normal racing circuits),
Dirt Ovals (only Bristol Dirt for now, short tracks but dirt. Sliding cars, close action, another world to anything else)
Cars are essentially silhouettes in modern day. They were 4 speed, H-Pattern, open-bottomed bricks. Starting 2022 they will be 5 speed semi-auto-stick-shift, sealed aero floor with diffuser. Racing will change next year, nobody is quite sure how.
-Indy 500
One of the few oval races on the Indycar calendar. While Indianapolis is a Superspeedway it races nothing like Daytona. Draft is still vital but pack racing is not the name of the game. Staying out of trouble and on the lead lap definitely is though. This racing is 220mph+, fastest in the world.
Cars are open wheeled but with the screen as of the last few years.
-Indycar generally
Mostly road courses, very few ovals. There are differences between road/oval like Push-to-pass, but road racing is as you'd expect.
-Le Mans 24 Hours
Cars and classes are similar to Daytona 24. GTE AM and GTE PRO. GTE cars are slightly different to GT3 and slightly faster, LMP2 is present as well, very similar as in the Daytona 24. Top class is now Hypercar, with the option for cars classified as "LMDh" to come over from the top class of the Daytona 24 and race in the Hypercar class.
The circuit is unique. 2 minutes 30 to 3 minute lap times (depending on class) this is a large, long track. The track is also mostly full throttle. Raced partially on closed public roads (50%-66% of lap distance) as well.
As with any endurance race being near the leader with a car in good condition in the last hour is key.
This race is part of the World Endurance Championship (or WEC for short), consisting of endurances races all around the world with these classes. It's a good championship.
Other Stuff
-Spa 24 hours, GT World Challenge and Intercontintal GT Challenge. GT3 (mostly) class races with differences in classes being mainly in driver rating. Close racing, lots of fun to watch. Mix of sprint and endurance racing.
-VLN/NLS/Nurburgring 24 Hour
The NLS (formerly VLN) is a series of endurance races held entirely on the Nurburgring Nordschleife. The cars range from GT3 to whatever-turned-up. 100+ cars is common in many, many classes.
While the 24 Hour is on the same circuit by (relatively) similar rules, it is entirely separate and is a standalone race. No championship points are applicable in this race, the fast cars turn up to win and only win.
If any of these appeal to you, have a look at previous races highlights on YouTube. Personally I like all of these, they're all good and interesting in their own way. Oval racing and dirt oval racing are entirely different worlds though, as a Brit it felt like I was relearning motorsports when I was getting into that.
Any other questions, feel free to ask!