Is there anyway i can put my every entry of username in a file like this e.g. using any auto number generation with every entry

1. Test
2. Hello

After i put them in a file like this i want to search and delete based on the numbers. e.g.

Please enter the number to delete the data: 1
"should delete the test from a file"

Please help. As any suggestions and location of any website will also be helpful.