Took lantus 2 times today instead of humulog

I just got diagnosed with type 1 diabetes. Had diabetic ketoacidosis at over 600!! Hospital discharged me when its in 200-300 range I know lantus is once a day. Today the hospital gave it to me this morning around 8 or 9am Fast forward to discharge around 3 At 6:26 I took 3 units 231 glucose At 9:16 here in cali time, I took 5 because of 319. Trying to get my blood sugar lower I noticed the lantus was the long acting and I mixed it up it was a busy day getting all my prescriptions and running errands.

What do I do? When should I check my glucose again like 3 hour rule?? If it gets low I know to eat or drink sweet! It's my first day and I'm just being so nervous.