I am a tanker who’s unit doesn't currently have tanks.So my unit is encouraging me to attend a school. What schools should I consider?

If I were you I would take any course that will be advantageous in the Civilian world. Maybe go to college or Trade school.

I won't tell you go to any school, but rather choose a school that will enhance your MOS knowledge and build discipline. Airborne and Air Assault will give you bragging rights, but most tankers won't even care so it would just be a personal achievement. If I were to recommend anything it would be to take college classes. Take something that you can carry with you where ever you go, military or civilian!

How is it that your unit in 2-69 Armor BN doesn't have any tanks?

Have you considered Drill Sergeant Academy ? It's MOS-immaterial. Provided you're in good physical condition and can get a leg up on the modules before you arrive, it could be a real career boost

Go to the Master Gunners course. Fits your MOS, and will help with promotion.

I had to laugh at your statement "I am a tanker who’s unit doesn't currently have tanks. I worked in the Intelligence community for 11+ years of my 20+ year career as a tactical data system admin. One of our favorite lines was "I'm in an Intelligence unit that doesn't currently have any intelligence." Of course some would argue that the term "Marine Intelligence" is an oxymoron. As far as school, anything you're qualified for that you think will help your military tour, or your civilian life after. I have two buddies here at the VFW... one was an air conditioner mechanic in the Army. The other was water filtration and plumbing systems in the Navy. Both of them are making $$ 6 figures $$ a year, and don't have enough time to get to all their customers. Good luck with your service time.

CBRN school at Leonard Wood. Back when it was NBC school there were a number of short courses. Not sure about today, but may be worth a look.

Closest I ever came to ground pounder was being assigned to an LHD. That said, here's a couple of questions for you:

Do you intend to make a career out of the military?
If not, have you given any consideration to what you want to do when you are no longer "in"?

A lot of folks in the Service have positions that are difficult to translate into civilian skill sets. While leadership and management skills are useful everywhere, it is often worthwhile to think about what happens "after".

You haven't given enough information in your OP to provide targeted advice, but I would be thinking about where you go once you get out.

I am a retired (from Federal Government) IT Specialist/Project Manager. If available, I strongly recommend Cyber Security and or anything in the Database arena. Albeit there are multiple layers in the IT arena, securing the systems and maintaining information/data is always going to be in high demand in the Military and the Civilian sector, no matter what changes occur, Security and Data are always going to be in the mix at multiple levels.

Everyone's suggestions are good. The real question is where do you want to go from here? If you're thinking of making the Army a career and staying in for 20 years, look towards schools/MOS's that give you an opportunity for advancement, as long as you can qualify for them. If not, look towards education/MOS's/schools that can translate to the civilian world. Even if you plan on going the career path, I would still get that education/experience that can be used in the civilian world, at some point. Whatever experience you can get while in will translate to credited experience when you get out in the civilian job market. That will give you an advantage over other job applicants and may even translate to higher starting pay. For example, if you transition over to a clerical MOS and do that for 2 or 3 years, or however long, and get out, then you will have 2 or 3 years of clerical job experience when you apply for civilian jobs. When I was in, I knew several combat arms SFC's and MSG's who had 17 to 20 years in the Army and had no idea what they would do when they got out because their jobs did not translate well into the civilian job market. They were regretting not thinking about it until it was too late. This is a long reply, but the bottom line is think about what you want to do when you get out of the Army (whether that's in the near future or distant future) and aim to get experience/education to further that goal. Good luck!