The new pay rates won't go into effect until the contract is ratified, but new hires will receive backpay.
Not sure if non-management employees qualify for tuition reimbursement before reaching seniority, but you typically have to send in the request within 30 days of classes starting and the grades/receipts within 60 days of the last day of the semester.
Read, read, read! Go look up the contract! As for tuition reimbursement that depends on your hub, at mine we are eligible on the first day we start. Have you even go through a interview? Or are you just lazy and didn't pay attention?
You should probably apply before the new pay rate becomes widely known and it becomes more difficult to land a position. My understanding is that the difference between current and new pay rates from August 1 forward will be back-paid whenever all new contract supplements are settled. Make sure the center or hub you want to be at even offers tuition reimbursement.