In Korean, to say “and” at the start of your sentence, use:
For example:
I am American. And I am smart.
I like cake. And I like donuts.
To use “and” at the end of a sentence in order to extend it, attach “고” to the verb stem.
The sentence above can be written as:
I like cake, and I like donuts.
You can also simply use commas to write the above:
I like cake, pie, and donuts.
When using “고” with two action verbs, “고” can translate to “and then” depending on the context.
Or, more naturally, “I go home after dinner.”
To use “and” in the middle of a sentence, aka between two nouns, use:
Examples:
I want to go to Korea and Spain.
I like cakes, donuts, and pies.
과 and 와 can also mean “with” in some contexts: