Loss of power , electrical, will run and start for now but revs

1994 olds sil. started about 3 times in 4 months, started it and ac wasnt blowing and no spedom. abs light on and orange circle light on, no power to power windows, no rpm , turned van off restarted fine. did it while driving 2 times for a few seconds but was still driving fine. did it when started once and didnt stop, ran but wouldnt hardly go and when got to maybe 30 or 35 it went back to normal. now it did it while driving and didnt go back. i have no power to start till i can build up to maybe 30mph, windws wont roll up, speedomoter says 85,other times it stayed 0 when it happened, no ac or heat or blower, no rpms gauge working, lights and signals do work, dome and glove lights work. just revs up fast but goes very slow till about 30. please give me help with what to look for, cant pay to have it fixed now and have to drive my kids to school, we live out of district so no bus service and nothing else to drive and nobody to help.