I know a bit about the subject and here's my advice:
1) Take care of your will and heirs - sometimes it's called "estate planning". There are cheap options online, with the risk of making some terrible mistakes. Hire an attorney with lots of experience doing this, and ask him/her to setup a trust for you and your family. Make sure you fully understand the tax implications of what you're going to setup.
2) The biggest risk of a large sum of money is trying to manage it and allocate it all at once. Imagine that investing or managing money is like a sport, and you have pretty much never trained for this. What would you do? You'd take it step by step. With money, slow down and take a decision at a time.
3) 8M is in the range of "f*ck you money", which means it gives you complete economical freedom for your life, and probably for your heirs too. It's probably wise to maximize for "survivability" of your egg nest, rather than trying to make even more money. Therefore, be conservative when deciding where to invest.
4) Diversify: like redundancy for high-availability IT applications, you need at least 2, possibly 3 quite independent asset classes to invest into (e.g. real estate, stocks, bonds, cryptocurrencies, foreign real estate, etc). Unfortunately, common wisdom about how to properly diversify is debatable to say the least. Spend some time reading and learning and try to come up with something satisfactory.
5) You might hire an investment manager, I am not a big fan of most of these guys, but it might be a way to learn, and you don't need to allocate a huge sum with him/her (perhaps less than 500k?).
6) Make sure you and your wife are 100% aligned with your "money" strategy.
7) Don't make it too public that you own $8M. It's not unheard of in certain places like Silicon Valley, but at the same time, when people know you're rich, they take for granted that you can afford things and that you are supposed to contribute more to other things. Certain relationships become a bit complicated. Just keep it for yourself.
8) Make sure your "IT security" is safe, especially if you will end up owning cryptocurrencies, but also in general.
9) Other than this, enjoy your life. Money is to buy freedom.
10) Finally, if you think you've been given a nice hand by fate, why don't you commit a small fraction of that (2%? 5%?) to doing good for others. Pick a charity, or even better, take a year off and volunteer somewhere with your family. It could be great.
I am no way as rich as you are, but I have enough to be able to "buy" me time with what I have accumulated in the past few years, and that allowed me to do what I wanted to do. It didn't go as expected, but I don't regret it.
At the same time, when you didn't grow up with money in the family, it can be surprisingly hard at times to deal with large sums earned quite quickly, like in your case. The worst parts might be dealing with your partner/spouse, dealing with your friends, and dealing with big recessions where you wipe out maybe half of your net worth.
Good luck.