First of all the PTA is not run by the Principal like a PTO.
You need to look at the PTA rules in your state. Find out what your rights are for working with your Principal and your campus.
The best way to work with the Principal is always to request what it is the Campus is working on this year (the Annual Campus Improvement Plan) and onward for the next 4 years.. There should be a Campus plan that the district requests.. Get a look at it.
Then ask the Principal how the PTA can help meet these goals. Maybe consider picking one of the goals to concentrate on. Make a plan and present it to the Principal.
The other thing we always did at the end of a school year was to send out a survey to Teachers and Parents. No names needed to be signed to these surveys, so people could be honest. It asked about what people liked, what was needed to be improved and what was needed to be dropped or totally changed on Campus.
The teachers were asked what they needed or wanted for their classrooms. Some teachers needed new sets readers (sets of books for their studies) . Some wanted the Exercise balls for the students that cannot sit still Some wanted money for field trips to expand a certain section of study etc..
Remember to also ask the "Special area" teachers also..Library, Music, Art, PE, Foreign Language and Special Ed
One of the first years our daughter was at the elementary school was to make sure EVERY classroom was being taught with the "gifted and talented curriculum". Goal was met and is still going today. New teachers not certified in the curriculum are provided with the supplies needed and the training. We try to provide the stipend to send them to the training or school.
Way back when ~ One year at our school one of the goals was to have better communication between the teachers and every parent at the school. Goal met, this elementary was the first elementary school in Texas to have a technology room with its own website. The parents also took computer classes on campus also.
One of my favorite projects is when the teachers decided they wanted to stop the bullying and decided to use the "Character Counts" Curriculum.. This was a collaboration with parents and teachers. Lots of volunteers and lots of planning. There was no way the teachers would have had time to organize and implement this. The PTA gave a stipend to a teacher to take the course in Calif. one summer and take this course. She was already going to fly out there with her family to visit and stayed with her inlaws so she also paid for her own flight. The PTA and Principal together worked with the district to get them to pay for the Curriculum since it was part of the Campus improvement plan.
Another goal was to meet the districts rules on the expectations for every student in school to be given (taught) to the students.. We worked on posting the information in every classroom in the school handbook, on the website and again, informed the parents every school year.. This is still part of the beginning of each school year.
Most times it is not money that is needed, but more parent involvement. Helping to train parents on homework and how to help their children study, How to help a child get organized. Holding information nights of children.s behaviors and what to expect of them. We would bring in guest speakers. We would make up hand out packets.
If you cannot get your Principal to move, then the PTA can come up with their own goals for the school for your projects/.
Of course Curriculum cannot be changed or added, but if you find a project you all decide the school needs you just have to inform the Principal and make sure it does not disrupt the every day working of the school. You can even go to the Principals Area Supervisor (their immediate boss) to also inform them of the plan.
I hope this helps. At each school the PTA is there to help the campus reach its goals. It always helps when thre Principal is always included, but a few may feel like they are being invaded.. So be sure to let them know you are there to help the whole campus.. Stay organized and keep the communications open..