Yes, you can enter the circle

The resilient sphere effectively excludes anything it encloses from outside spell effect areas. As the effect of the magic circle originates outside, it does not have any effect on a creature rolling inside the sphere, as it is not considered to be in its area of effect.

You can teleport or plane shift out of Otiluke's resilient sphere

Provided that the caster is the one inside the sphere teleport will work. Teleport has a range of 10ft so it's area of effect will be limited by the bounds of the sphere so the caster and any targets must be inside. Teleport says:

This spell instantly transports you [...] to a destination you select.

This effect is not a movement effect, you aren't passing through the sphere. You instantly appear somewhere else.

Similarly Plane Shift has a range of touch and does not require a spell effect to travel through the sphere. It says:

You [..] are transported to a different place of existence.

Traveling to another plane does not require moving through the sphere. So you can Plane Shift out of the sphere. Misty Step, Thunder Step and any other teleportation effects will all work.

Interestingly Etherealness will even let you pass through the sphere itself as you are no longer on the same plane of existance though you can percieve it. We know this because Etherealness says:

You ignore all objects and effects that aren't on the Ethereal plane, allowing you to move through objects you perceive on the plane you originated from.

As you suggest spells for which this doesn't work specifically say so, as per Force Cage's description:

If the creature tires to use teleportation or interplaner travel to leave the cage, it must first make a Charisma saving throw. On a success, the creature can use that magic to exit the cage. On a failure, the creature can't exit the cage and wastes the use of the spell of effect. The cage also extends into the Ethereal Plane, blocking ethereal travel.

Otiluke's resilient sphere does not contain similar text and spell's only do what they say they do. Therefore the sphere does not prevent teleportation of interplanar travel.