Biz tax is a deep topic. Short answer is the LLCs are passthrough, which means you'll receive a k-1 from your accountant that you include in your personal return.
Quick strategy tip: have your accountant apply for S corp status for your LLC. You'll pay less tax right away.
I'm assuming you are US-based. If you receive compensation in stock, no matter the currency denominator, it is income and is therefore subject to income tax.
Your employer should produce a W-2, and your share grant will be included.
First thing: don't be so hard on yourself. Everyone gets anxious in interviews because the stakes are high and the interviewer has almost all the power.
Some things that I've seen work...
1) do lots of interviews. Once you get used to the (awful) dynamic and realize it's the process, not you as a human, that's wrong, it feels a little more okay to fail, which should reduce anxiety
2) meditate before the interview. I like the headspace SOS meditations.
3) work on open source projects. I've seen this be the deciding factor not due to some vague community contribution, but because your potential employer can see your code and because it's been peer reviewed. This command a certain flavor of local celebrity that can be very powerful, especially if you slay in that domain.