Some US universities require the SAT or ACT standardised tests.
If you go the website www.fairtest.org it will show US universities that do NOT require the SAT or ACT. Please check with the universities individually as well.
For the SAT, register at collegeboard.org
For the ACT, register at actstudent.org
If you would like ACT/SAT tuition, Guidewell Global is a specialist organisation based just around the corner from the school on Crawford St. They are partnered with the Fulbright Commission.
To help you choose the right test (SAT or ACT) Guidewell have a bespoke Diagnostic Test, free to Halcyon students. Students can take the test online here: Guidewell Global