Fun things to do for immersion in your target language
Some things you can do in your target language that are fun and make you care more than when reading a textbook:
Cook a traditional recipe
Find a video in your target language on how to cook something you like from somewhere that speaks your target language. The motivation here is obvious- if you don't understand the recipe you won't be able to make the dish. Watch it once to find out what the ingredients are, and again when making the dish. Use your dictionary of choice to help out if needed.
I prefer turn-based games with RPG elements as I get a mix of dialogue and utility words like save, menu, attack, etc. Right now, I'm playing Dicey Dungeons in Chinese and Pokemon SoulSilver in Japanese (hiragana only). The consequence here is obvious, if you can't navigate menus or choose the wrong attack, the game will be harder.
Hard mode: Find a server with voice chat in your target language where teamwork or communication is important. Any MOBA or MMORPG comes to mind. You'll learn to communicate on the fly, and you'll learn a plethora of the foulest swear words imaginable.
3. Share your personal interests with others
Learn to talk about things that you do that are unique to you. Standard language courses teach you words that tend to be generally used: eat, sleep, drink, etc. What about things that are of special interest to you? Chances are, you will use this vocabulary more often than the average person, and you will be more passionate about the subject- this leads to higher motivation to retain this specialized vocabulary.
Then post it wherever you want, or in a diary, or talk about it to a native speaker.
Recite and rehearse jokes you find funny. Jokes in other languages reveal so much about the underlying culture that can't easily be translated. By understanding how to tell a joke in another language, you will gain more appreciation for the language itself. The upshot here is that telling a joke comes with social risk, so you will have to build the confidence before delivering the joke.
Bonus: Foreign language puns are hilarious.
5. Listen to a local radio station
Local radio stations have it all- interviews, ads, music, traffic updates, and more. Many of these are available online, so no need to move to the city and pull out your FM receiver! What's especially nice about this option is that radio hosts tend to enunciate and use proper language. Even if you don't understand every word, the grammar and structure of the language will slowly ingrain itself.
This is the most passive of the immersion techniques I use, but I've found many songs I enjoy through local radio stations. Then, I take a deep dive into the song lyrics and learn them, which is much more active. The goal is to learn the lyrics and rehearse them until I can sing along with the music.