The purchase of life insurance is not connected with the timing of your marriage; depending on his age and health, he can get $1 million or more relatively cheap. You aren't responsible for his debts, but his estate is. What is his estate? Anything he owns at the time of death. So, if you marry and purchase a home, depending on how it is titled, when he dies your home can be responsible for payment of his debts.
More information at:
State of Florida.com - Florida Probate Guide