First practice with new team coming up

We are a 12U TB team and have our first practice of the new season coming up in 2 weeks

We have 5 returning 12U, 4 moving up from the 10U team (all of which i coached 2 years ago), 2 coming over from another good TB organization and one girl new to travel ball.

I'm trying to come up with some creative things to do from day one so that I will be able to measure who is progressing and at what pace, examples would be:
1. timing them home to home at first practice, then doing this every 6 weeks or so to see who is improving their base running
2. throwing speed via radar gun
3. ground balls to SS and clocking them from ball contact to glove to see who is improving their ball transfer, charging balls and making plays...

I'm looking for any other ideas you can come up with and also any suggestions for what you do in your very first practice.

My AC and I are very excited to get going with this team, lots of ideas pumping in our brains... Team mantra is HUSTLE and we are going to start with that on day one.

You might be over thinking this.

Have a practice plan where none of the players stand around, they are always doing something.

If you are doing some of the timing things in my head I see 11 players standing around cheering for the 1 player.

If you do not give them an opportunity to mess around they will figure out the hustle part. It is really on you to be organized.

We incorporate stations in our practices to limit standing around and we are extremely organized with a game plan before each practice (hence the brainstorming going on now) tee work, infield work, outfield work etc.
i envisioned these things being done either as a station by one of our helpers or at the end of practice as we're having a pizza party and parent meeting on the first day and this would be a perfect opportunity to get it done.

I want the kids that are improving as individuals as well as a team... example being while you may not be faster than others, you are still personally improving YOUR time ... which also helps the team.

looking for ideas to get the kids excited day 1

Day 1 DD is always excited; it is day X where things sometimes fall apart when the coaches get lazy.

Like you said it is a long journey not 1 practice.

You'll do great. If the girls don't all know each other start with a fun fast paced get to know you game. Then quickly explain a rules and get started. It'll be great