Where can I go to type a letter
Your local public library probably has computers available for public use. Phone ahead to ask if you need to reserve some time.
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You can do it in your room, the kitchen, bathroom even. Pretty much anywhere.
what did you say >[ '_' ]< please give a little more info
If you do not have a computer and printer, try the library. Have no idea where you can find a typewriter today. Sorry.