Hello Joyce! I put up a retractable clothesline that works well for me. It Is attached to a small shed in my yard and I have a hook in a nearby tree that it attaches to! It's perfect for my needs and I can retract the clothes line away when it's not in use. You can buy a single line retractable clothesline or you can buy one with more lines. They are available at Amazon, Home Depot, and Menards. Here is an example: https://www.homedepot.com/p/Everbilt-40-ft-Retractable-Clothesline-72917/206094320
Congrats on using a clothes line which is still pretty common in Europe but rarely do I see them in the US (always looking so I can take photos) ... although I remember hanging clothes as a kid, and the line went from our porch to a tree in the backyard.
So I did some digging and found there are lots new clothes line so it really depends on the space you have and the style you want to use.
So good luck Joyce, on deciding which approach to use and share back here including photos.
PS I found this fun video made in the UK that shows you how easy it is to put a post in the ground for a clothes line. My only added caution is if your ground freezes, you'll want to use a longer support tube to get below the frost line ... so just check what's recommended for deck posts (or mailbox posts) in your area.
You will need 2 things to hook either end of the string to. Trees?