Did your Savage 64 come with iron sights? If so, IMHO, it would be a good idea to practice with them for awhile and get used to the gun's behavior and capabilities. You might find you like open sights. You can always add a scope later.
If the 64 did not come with iron sights, it is probably already drilled and tapped for bases and rings to mount a scope. It is not hard to do, but many shops will mount and bore sight a new scope for free or a nominal charge if you buy one. For a first, that might be the way to go.
There are a lot of scopes out there. In general, the more you spend the more you get, but you can get reasonable first gun performance from a budget scope. 3-9 zoom is common, but 9 zoom is a bit much for a rimfire, so if you get that zoom, start off by using the lower powers.