This is a very difficult one.
By your own admission you have not been good financially so giving advice to others could be difficult, particularly your own children.
Also the children may resent it, perhaps them feeling that you are suggesting they are having (or are going to have) problems.
Sadly some people are good with money, others bad with money.
I have two children from my first marriage, and both now about 40 years of age (one a bit under 40, the other a bit over 40).
One has always been good with money, rarely going in debt, always finding the best deals on credit cards and banks, getting good mortgages etc.
The other has always been bad with money, Even when he was 18 he took out a loan to buy a car, wrote the car off fairly quickly, then spent the next few years paying for a car he no longer had.
He is always in debt and maxed out on his credit card, he gambles so wastes money that way. He married lady who was also bad with money so they are both always overdrawn at the bank and maxed out on their credit cards.
Both my sons got left a LOT of money when a relative died (a few hundred thousand).
The sensible one put it in a house and now owns a house worth about £500,000.
The other one bought a run down house, spent a fortune doing it up and sold it at a loss (because he needed the money).
He then bought a second house, spent another fortune doing that up and sold it at a loss (he says he made a profit on it but I think he is deluding himself how much he actually spent on it).
He and his wife are now living in a rented house costing him over £1000 a month.
He has started a number of business over the last few years that have all gone under.
He now runs another business where he had to spend thousands for stock and while he is now bringing in money he is having to undercut people just to get the work.
He has a few large bills to pay (VAT bill, tax bill) and I suspect this business will go under.
My other son (the sensible one) worries that his brother and his wife and two children will turn up on his doorstep with their suitcases saying they have run out of money.
So while you can pass on advice, some people are good with money, some not.