Online dating applications are like a big playground where grown-ups can find other grown-ups who they might like to play with. The playground is on the internet, so you can play from wherever you are by looking at pictures and reading some words that other grown-ups have put there. The grown-ups on the playground are looking for different things, like someone to play with for a little while or someone to play with for a long time.
You, as a grown-up, can make your own page on the playground so other grown-ups can see who you are and what you like to do. You can post some pictures of yourself and write a little bit about your personality or your hobbies. You might say, "I like to ride bikes" or "I love dogs" so that other grown-ups who like those things might want to play with you.
When you see someone who looks interesting to you, you can "swipe right" or "like" them to see if they "like" you back. If they do, you can start talking to them using messages on the playground. You might say, "Hi, I like your dog in your picture!" or "I see we both like to ride bikes. What's your favorite trail?"
Once you start talking to someone, you can decide if you want to play with them in real life. You might want to meet them for coffee or go to the park with them to see if you really like playing with them. If you do, you might want to keep playing with them on the playground, or you might want to stop playing with them and look for someone else.
Just like in a real playground, you should be careful when you're playing on the internet playground. You should never share personal information like your address or phone number until you really trust the other grown-up. You should also be careful about meeting up with strangers in real life. Make sure you meet in a public place and let someone know where you're going and who you're meeting.