When I moved here and before i got my chickens, I called my county extension agent (in the phone book under county government) to talk to him. He put me in touch with a professor that teaches chicken diseases at the State Landgrant University, That professor also is on the team that investigates reported chicken diseases in the area. He breeds chickens and has shown chickens. We had a nice chat.
I explained how I planned to manage my chickens. I keep a closed flock. That means the only new chickens I get are either hatchery chicks shipped in or from eggs I hatch myself. I do not show chickens so mine are not exposed at shows. I do not participate in chicken swaps. All these reduce the chance of bringing disease into my flock.
We discussed what diseases are prevalent in this area. For example, there had been one reported case of Marek's in this county in the previous two years. I didn't consider that a huge risk. At the end of the day, I wound up not vaccinating them for anything. The hatchery I used had a $10 minimum to vaccinate any of them for Marek's. I used that money to buy 5 more chicks. Some people live in areas where Marek's is really prevalent. They need to get that vaccination.
I don't know if that is the right decision for you. I don't know how you plan to manage them. I don't know what is prevalent in your area.
I don't know where you plan to get your chicks or what vaccinations are offered. Most of the hatcheries we use offer Marek's. Some offer vaccinations agianst some (not all) strains of Coccidiosis. You might be able to get them vaccinated against Fowl Pox. I'm not really aware of any other diseases the hatcheries we normally use will vaccinate for. You'd probably need to do the rest yourself.
Good luck with it. It is a personal decision, not one I can make for you.