Hi @shanibeer !
To move HIVE into HBD, the simplest way is "Trade Tokens" on Ecency, as others have said. But the cheapest I've found so far (apart from author rewards, lol) is through Hivedex.io - it's not a huge saving, but usually a percent or two better than Ecency, or if you're brave you can use it like a trading platform and tell it what price you want to buy at.
As for the main lessons for Hive newbies, I'd say the most important thing is to post regularly about what you love, and engage every day because you enjoy the engagement. Don't worry about the rewards too much for the first six months; they'll build up slowly and steadily and then one day you'll look at your wallet and realise the incredible impact of consistency x compounding 😀