Help, I wonder if I chose the wrong person to build my site. can I dm someone some questions to ensure I did, or didnt?

Thanks

I will have cloudflare for some security.

Questions,

1. Do i need more security than that

2. Do I need cache plug in?

what plug ins are recommended for the following?

-automated emails and marketing

-age 21 plus acknowledgement

-seo

-speed

-gated checkout

i keep hearing people say they can use prompts and just dump it into the server - but it is not going to just build my theme, plug ins, etc, correct?

Thoughts? which is better? I do want to keep as much speed on the site as possible but not sure that either will make too big of a difference?