I read up until "what should i do about a tag..."

1. You have 2-3 days from date of sale to put insurance on the vehicle purchased.
2. If you have previous insurance from another car already, you have 14 days to transfer it.
3. You have 30 days from the date of sale to tag the vehicle bought. Within that 30 days you have to pass emissions for vehicles 1983-2005, and have min. Liability insurance.