Not a stupid question at all.
Yacht clubs generally do not have people who can work on your boat if you need it. Sure, you can maybe find another boat owner to help you do something that can be done while the boat is in the water but if you want warranty work done, or done by a professional, you'll have to move the boat to that location. Additionally, if you're in a location where the boat has to be hauled for the winter, some clubs require that you take it elsewhere for winter storage.
When we bought our boat we knew it needed work so we chose to at least start out in a marina with a yard that had a good reputation so that we wouldn't have to move the boat somewhere else to get the work done (especially important since we live 2 hours away).
Yacht clubs are great for the social aspect, most have restaurants and bars on site, club races, cruises, etc. Many also require members to commit to a certain amount of work hours per year, help with building upkeep, or whatever. Not a big deal in my mind but something to consider as many have memberships where the member "owns" a piece of the club. Most yacht clubs have "social" memberships at a reduced rate so you can experience the social part of the club without taking and paying for a slip.
For now, we're sticking with the marina. Restaurants are within walking distance and we have good neighbors. Also, the location is good for our commute and for easily getting into the Bay. Still, when I come across an interesting yacht club I do check into their membership requirements, just in case.
Yacht Club vs Marina.
Donna has stated some of the differences. A Yacht club will tend to have commradiere and a social aspect to it as opposed to people comming down holing up in their own boats a just going out. Somethjing else to consider is that is usually reciproicity between yacht clubs. Here on the Chesapeake that is a large reduction in the price of transient slips as well as first chance at a transiet slip over a non yc member.
Of the over 125 YC on the Chessie about 80 are sailing clubs only with no real facilities. I have found that most clubs do not require any working at the club to maintain membership. Yes there is a definate voluntary feeling as we actually own our club ( 114 members) and we help with the governance committtees whic set its fees as well as policies unlike a maina where that is just dictated to you. Our slip cannot be given to someone else next year unless I want to move unlike a maina. Our fees do not increase unless the majority of members vote for that. We do have beautification days, crab feasts, bands, happy hours, reduced drink and food prices. Our boats are also well protected as only memebers are really allowed on club grouds vs the genral public wandering in and out.
Most clubs....and marinas as Donna stated do not have working yards. Thats good and bad. You have to have someone to come to work on your boat or take it to a yard nearby. On the other hand you arent bothered by machinery or people pounding painting and lots of construction. We pull our boat for the winter ( every three years) at a facility about 1 mile away so no biggie.
If your are looking for some social interaction and more than a parking spot for your boat a club is a good place to go. You actually have a say there. It all depends on what you needs or priorities are. Yacht clubs and marinas are all different so its ahrd to make general statements about both as many marinas are really nice places also. Check a numbber in your area. get a feel for it and look to see how the facilty deals with its upkeep.