Price Per Person?

The price per person usually refers to all inclusive venues that will provide the catering (cocktail, dinner, desserts, cake) and bar service. The 3500 price may be just to rent the space without the other services included or it may be for the ceremony portion if your having it all in one place. I’d reach out to them for clarification.

The $3,500 is the price to rent that venue space. The per person cost typically comes in when you are talking about catering and/or alcohol. So, you will pay $205, per guest, if you select that specific catering option or package.

You are on the right track. It means you pay $3,500 and $24,600 ( 205 x 120) for 120 people, guests and wedding party, to have the space, and the catering package they listed, which likely inçluded food, average liquors, and basic tables, chairs. Check the package to see if only one color linens, other things are covered. You might find they have upgrade fees, cost more for nicer or special colors or types. Sparkly tablecloths may cost $10 more per table.
Also, on that $24,000 catering bill, be aware that most states tax restaurant or catered meals, 8-10%. That would add $1968 - $2,400 more. And the gratuities for serving staff would be 20% minimum, or $4,920 more. Some venues charge an administrative or gratuity charge for the manager, Day of Coordinator, others. Some don't. Your $205 per person includes plating cake and serving wine if your package includes them. But if you use a different Baker, or wine source, they will add a fee per person for serving it. Find out the percentage of tax in your state. It makes a big difference. Check for administrative gratuities not going to service staff. And do not make the very common mistake of counting invited guests but forgetting to include yourselves. Or wedding party.