Hi Linda,
That all sounds ideal, and suggests a good path to choose. You have a
school that will support after-hours club activity, give access to labs,
and you have the hardware you need to make some forms of lab equipment
right away. For the stuff you'd need to pay for, I'm sure your school or
a local college would support you!
If there's a local College or University who have fielded an iGEM team,
they might be willing to support a "junior cycle" team in the local
high-school if you ask, too.
Coursera/edX is good idea, I think, but don't wait until then. The
internet is a great source of critical information, too! And for an
ambitious club like this I'd be surprised if a local person wouldn't be
willing to teach out of hours; whether a postgrad at local university, a
researcher, or simply an enthusiastic teacher.
So, go for it! Great idea, and exciting to see how close you are already
to getting something together! :)