How do you connect the cold water to a refrigerator?

I purchased a new fridge more than 6 months ago and I still haven’t hooked up the cold water line. Do you have any experience doing these type of connections? The house I am living in was built so long ago back when the city was just being built maybe right after WWII. At the moment there is a ¼” copper line connected to a lead water pipe behind the fridge. It has an old needle valve connected to it, but the whole thing doesn’t work. I don’t have the resources to pay a plumber now. What can I do to best tackle this job?