I suppose if you live in a very dark area, you may be able to see some of Jupiter's moons with only the naked eye, but for sure you will be able to see them with a good pair of binoculars. For the best views, a telescope will do the job nicely and it doesn't need to be a huge one. Of course bigger is always better. These following pictures (that I borrowed off the internet) show what you would see. I have seen Jupiter though my telescope many times and it never ceases to amaze me and each time I look at it there is something different, either the planet itself or the location of its moons. It is not uncommon to see the shadow of one its moons on Jupiter's surface. (Jupiter does not have a solid surface as we know it, it is a huge ball of gas, so the shadow is projected on Jupiter's cloud tops). By the way, Jupiter spins really fast. It rotates once in less than 10 hours and that is spectacular because of its huge size. It could hold 1266 Earths in its volume. This fast spin alters its shape from round to wider around its equator than around its poles.
Here is the first picture. Notice the shadow of one of the moons?
And a view with the moons in a different location:
Now, tonight (if it is clear), go outside and look up. Jupiter will be straight overhead.
Did you ever notice that on a real clear night the stars twinkle? Well I have and a couple of them stood out because they didn't twinkle like the rest. These non twinkling stars are planets. Planets do not twinkle. Now don't forget to take a look at the sky every night that it is clear. You may like it and it may become a habit. Of course it could give you a pain in the neck (grin). Now have a great day, you hear?