Gear sold for scuba will on average be better quality than the stuff marketed more for snorkeling. If you buy scuba stuff it will be ok for snorkeling. "Snorkeling" stuff may be ok for scuba, or not.
You always want a well fitting mask that doesn't leak, with tempered glass. A less expensive mask sold more for snorkeling can work just fine for scuba if it fits you. (There are lots of threads here that describe how to properly fit a mask so I won't repeat.) You also want a "low volume" mask for scuba so it is easy to clear. I've seen some people buy high volume masks for basic snorkeling (think fish bowl on your face) and they're ok for that but not great for scuba as they are hard to clear the water out. Some snorkelers and new divers also tend to go for masks with purge valves. That's ok for snorkeling and for some divers they make sense. But purge valves can have a number of drawbacks for diving and once you learn it is very easy to clear the water from a mask without one.
Fins - you can always snorkel in scuba fins, some may work better on the surface than others but it's not a big deal. But there are some smallish lightweight fins sold for snorkeling that aren't very suitable for scuba. When wearing scuba gear you are pushing a lot more stuff through the water and wimpy fins won't cut it. And sooner or later while diving you are likely to find yourself in a situation like a current where you really need more power. Also a lot of full foot fins intended for warm water are sold for snorkeling. While there are certainly good full foot scuba fins that are great for warm water scuba in some cases, fins with adjustable straps that you wear over some sort of bootie are more versatile and pretty much required for cold water, or for shore diving from rough terrain in warm water.
Snorkels - people have lots of arguments on whether features like purge valves and gizmos for keeping water out are good things or not, and you will undoubtedly develop a preference. (I personally prefer a rigid semi-dry snorkel with a purge and simple splash guard on the top for actual snorkeling, and a separate roll up snorkel that I can put in a pocket while diving.) But bottom line is that anything will work, and if you're trying to save money this is a good place to save it. Realize that lots of people don't use a snorkel at all while diving once they're past their OW class, because they are rarely used but tend to get in the way and make your mask leak, especially if they're bulky. Some people do continue to wear snorkels because they are used to it or use them a lot on the surface. Other people like to have a snorkel on them, but keep it someplace other than wearing it on their mask.
