BBH is a token. When you have enough you can tip others, without spending your own. That is done with the !BBH command. It also send you other tokens on a weekly basis (saturday). This is a drip.
Hive account@bradleyarrow is the man for the BBH project.

Voting for posts:
Under each comment, post, basically all text by people, there is a circle with an arrow-like thing in it (pointing upwards). If you click this, you can vore for the comment or post.
The more HivePower you have, the more value to your vote.
HivePower is staked Hive. You can do this directly from you wallet on Ecency or any other Hive app/site, basically.

PIZZA and LUV is not something I use myself, but as far as I've seen it's also a token that allow tipping others using the command !PIZZA or !LUV (notice that it's exclamation marks in front of it).

There are a few ways to convert/buy/sell tokens.

• You can swap, using a tool like this: https://beeswap.dcity.io/swap
• Convert (SWAP.HIVE to "regular" Hive or the other way around) using something similar to this: https://beeswap.dcity.io/convert
• Buy and sell tokens on a tool like this: https://beeswap.dcity.io/tokens

There also is a tool that allow you to sell all the tokens at once with some predefined requirements, but I can't find that just now. Thought I had saved it, but oh well.. time to look for it I guess.

Gaining engagement is just by staying active. Interact with others, comment on their articles (posts) etc.