What is the difference between Morjesta! and Heippa! and Heido! and Moi! and Moikka! ?Feel free to just provide example sentences.

they all mean hello and/or bye. the biggest difference is probably that different words are more common in different parts of Finland. we often use the same word to say hello and goodbye, or we say the word twice, but only when using "hei" and "moi", meaning they turn to "hei hei" and "moi moi" when saying goodbye.
"Morjesta" or "morjensta" is mostly only used to say hello.
"Heippa" is mostly used to say bye.
"Heido" is also used to say bye, but I think this expression is more rare.
"Moi" is the most common way across Finland to say hello, but can also be used as bye as one word or as duplicated to "moi moi".
"Moikka" is more commonly used as bye but can also be used as hello.
"Moro" is also one way to say hello and goodbye.
"Terve" is also a way to say hello.
"Hei" is always a good choice to say hello too, and to say bye duplicated to "hei hei" or as one word.