Any advice for a new Lieutenant, leaving BOLC and heading for their first PL role?

I agree with CW4 Hamilton, you have to be a sponge. Take your first 30 days to really take in the good and bad of your new unit. Do not be surprised if you don't immediately get a platoon. It is completely normal for a new LT to sit in the S3 shop for a couple of months prior to take a Platoon. And always listen to the advice of the senior NCO's in your unit, take what makes sense to you and develop your self as a leader.

There's a lot of great advice here... mine won't help make you better at your job, but is still a bit of professional development - drop the (P) after your rank. Promotable is not a rank, and is only to be listed immediately after your rank if you are promotable and filling a billet of the next higher rank. For example, if you are a promotable 1LT filling a CPT's billet. It signifies that you are receiving credit at that higher rank position based on your selection for promotion. If you were a 1LT(P) in a CO Cdr billet, you would receive KD time as a CPT. Generally, all lieutenant MTOE/TDA positions are coded for 1LTs as it is assumed you will be promoted, 2LT and 1LT are interchangeable and it does not count as serving in the higher billet.
Take it as you will, but you will see a lot of your fellow officers making that mistake throughout their careers. Don't get me wrong, being promoted to the next rank is an admirable achievement and I can't fault your for being proud.

Always lead from the front and take care of all of your troops but be stern when you have to be.

Find other Signal officers at your duty station to network with. They can help you with creating products, training requirements, and any issues you have. A good leader ensures their unit/platoon is doing everything right, but a great leader does that and ensures the other units/platoons are squared away as well. Be confident in your decisions, and always be open to suggestions.

Talk to your soldiers, get to know them. Counsel them and let them know your expectations. Give them growth and correctional counselings and lead them from the front!

First off, Congratulations on your new position as platoon leader! From an NCO that was been around for a while, I would ask that you listen to your NCO's as they have many, many years of experience. Remember that if, and when it comes down to the wire.. these are the men and women are the ones that have your back and complete the mission, so make sure to have theirs. Remember also that respect is earned, not a privilege. Thesse are just a few tips that might make the journey a little easier! I wish you well young Lieutenant!

Mr. Millican-Please allow me to first congratulate you on what I trust will be the start of a challenging and rewarding career as a serving officer. I will add to the invaluable advice offered by the senior enlisted professionals on RP who have wisely suggested learning as much as you can from your senior NCOs. As a former enlisted man yourself, use that experience, but avoid thinking of yourself as "other" than new to the job. You'll have an advantage over true "butters"...but it's a new view from a new post, and the more you listen, the more you'll learn and serve as a credit to your platoon and service. I would imagine that the NCOs who know you are prior service will expect great things from you; I would also imagine that your Platoon Sergeant will be eager and proud to train a willing Platoon Commander coming up from the ranks.