Heb 11v7

By faith Noah was warned about something that had not yet happened.
He obeyed God and built a boat that saved him and his family.

We only know around 0.1% of Noah's life (he lived 950 years).
God has ensured we have a record of why it happened - not how it happened.
We do not know the practical circumstances that led up to Noah being in the position to take on this task.

In the fall of Jericho Joshua 5 a few people were saved.
From the character of God we can surmise that all could have been saved - if they had turned to him.
In fact due to the Israelite's desert wandering they had had an extra 40 years to do so!

We are told of one incident with sorry consequences a few years after the flood - but what other sins was Noah guilty of?
Consider the example of Abraham.

Rom 4v3

God accepted Abraham because Abraham had faith in him.

Rom 4v5

God accepts sinners only because they have faith in him.

Psalms 25v6,7

Remember O LORD your longstanding mercy and love.
Do not recall my longstanding sin and rebellion.

My paraphrase to highlight the longstanding character differences.

I don't write novels or film scripts - but how would betray Noah?
Before the flood I would paint him as someone who had technical and business skills similar to Isambard Kingdom Brunel.
So when the time came he had the resources for the task.
Consider Joseph - a lot happened between his dreams and appointment as premier of Egypt.
After the flood - did he have some sort of breakdown which led to the alcohol issue (cf Elijah)?
Near the end of his life could he have met Abraham? Noah's death and Abraham's call are close to each other. We can read Abraham's call as coming out of nowhere - but had God been preparing the ground? Similarly Andrew and Peter did not leave their nets without warning  - they had been with John the Baptist and for those with eyes to see God had been preparing them for that day.

Heb 11vv1-3

Faith is being sure of what we hope for, proof of what we cannot see.
It was their faith that made our ancestors pleasing to God.
By faith we know that the world was made at God's command.
By faith we know that what can be seen was made out of what cannot be seen.

Faith is not trying to squeeze out of yourself a hope that things will somehow work out.
Put yourself in God's hands. Take your hands off the situation. Wait for Him.

Jesus taught his disciples to pray beginning 'Father' - as our heavenly father God has a responsibilty (yes He is responsible) for our wellbeing.
Leaving it to Him is faith.

James 1vv14-17

We are tempted by our own desires that drags us off and trap us.
...
Every good and perfect gift comes from the Father...

There is something I have my eyes on and want. I don't have the clout to keep my name at the top of the list and if I get to the top it would be financially very tight to see it through to completion. Do I just tear up the paper and tell them I am walking away? In Rom 14v23 we read 'Whatever does not proceed from faith is sin' - walking away would be a failure and sin to me. I look to God from whom 'every good and perfect gift comes' and whatever the outcome the result from Him will be better than anything I could put together myself!