The answer is that as long as you are not giving advice which is regulated, you are good to go. What’s regulated? Law, medical, actuary, insurance, investments, real-estate (in some locales), engineering (in certain fields), architecture, and certain trades. If they license the practitioners, they probably regulate the advice. For example, just try to practice accounting in Texas. They will be all over you if you are not a CPA …
Also, you have to be very careful that you aren’t issuing an opinion on certain things. Accounting is a clear example. If you start doing financial statements and attaching some sort of opinion that they are correct, the CPA board will be on your case.
Be very cautious about anything involving other people’s money. Giving advice about loans or real estate transactions can get you in big trouble if you are alleged to be an unlicensed real estate broker or loan broker.
Even if there is no regulation, you should be careful where some sort of dealer license is involved. For example, I had a client who helped people find the right car for a price. The state alleged he was an auto broker. Big cat fight ensued. He was finally absolved of any wrongdoing, but ended up quitting the business. Who needs trouble with nitpicking regulators?
Yes, we live in an overly-regulated, bureaucrat-dominated, legalistic society where the regulators are doing their best to protect us all from ourselves. Que Sera.