Be prepared to make mistakes as you learn. Read some of the advice found in this forum. Above all, be patient. I will say now that what works for me may not work for you. I would use copper wire but any kind would work. I don’t water my plants as much as some. I use an eyedropper to water my seedlings. About a teaspoon every few days for the first week or so. Put the water at the base of the plant. Once they have their first full leaf I switch to about a half jigger of water. I wait until the top of the soil is dry before I water. This will encourage the roots to spread out. Leave your seedlings in the cup for at least a month for autoflowers and a little more for photoperiods. You want the roots to start growing around the cup. I usually transplant when the soil is dryer. Give it a few days past your normal watering and if the roots are good enough the whole ball should come out easily into one hand.
Here’s a link to my blog: