T.F.
I've been a sub over 10 yrs in Plano.
If you've not had contact from HR, you need to do so. When a sub is accepted, you go to HR, submit forms, get direct deposit set up, complete profiles to let HR know what schools you will or will not sub, what grade levels, special Ed, ESL, etc. Once this us done and you go through training, you then get set up in the system and get your badge.
Once that is done, it's up to you as a beginning sub to get your foot in the door.
Most schools and grade levels have a preferred sub list. They dislike having to put a job in the sub "pool" because you never know what you'll get!
Try it out at several schools, several levels and see where your niche is then target on your niche.
I only sub at 1 of the 46 elementary schools. It's where my daughter went, 3 minutes from my house, and I am very connected at that school. I could sub 5 days a week but its not practical for me because I sub because I love it. I run our company and I only pre arrange my jobs which are not more than once a week unless it is conference or testing times. Subbing is a good mental outlet for me and helps me step away from the financial person I am with our company. It helps me balance everything out and I get to work with children.
I can say there is a shortage if subs willing to be a special Ed asst and that is a very good way to get your foot in the door. I love the special Ed so it was easy for me to start in that direction.
Start slowly and don't overwhelm yourself. The beauty of subbing is that you choose your schedule. Do you have children in school? Start by letting the school know you are beginning to sub. They may help you get in the door faster.
Good luck!