Been freelancing for 7 years, took my first W2 job and benefits enrollment made me feel like an idiot

Spent my whole 20s doing freelance video editing, mostly for small agencies and a few direct clients. My entire financial life was basically just income, set aside 30% for taxes, pay expenses, save the rest. That was it.

Just started a full time role at a production company in Austin last month and they sent over this benefits enrollment packet. I was half on my phone when I opened it and had to put it down and actually sit up because I had no idea what I was looking at.

HSA vs FSA, the difference between the two dental plans, whether to do the HDHP or the PPO, 401k contribution percentage, Roth vs traditional, life insurance multipliers. I know what some of these words mean individually but trying to make actual decisions with them felt overwhelming.

The HSA thing especially confused me because I kept reading that its a triple tax advantage but I don't fully get how you actually use it, like do you pay medical bills out of pocket and reimburse yourself later or do you use a card at the time.

Also have no idea what a reasonable 401k contribution is to start with. Company matches up to 4% so I set it to 4% for now but second guessing if I should be doing more since I'm starting later than most people who had this stuff in their early 20s.

Anyone who made the jump from freelance to W2 or just knows this stuff, what do you wish someone told you when you first enrolled