Select the first clip in the sequence by positioning the playhead over it. You should see it highlighted with yellow around it!

On the right are panels...click the Effects (Transitions) Panel

When a clip is selected in the sequence, the transition is applied at both the start and end of the clip.

When a clip is selected in the sequence, the transition is applied at both the start and end of Press CTRL + A to select all the clips in the sequence and then choose cross dissolveclip.

Deselect all (or simply click on the first clip) and select the first clip again, and this time I'll choose the BLACK preset.

The first clip will simply fade up from black, but when it's placed between clips, this transition fades the outgoing clip to black and then fades up on the next shot like a blink.

Drag the dip to black preset from the transition panel and drop it at the end of the last clip.

Another useful transition is WHITE, which works a lot like BLACK, but as you'd expect, fades the image to and from white.

We will add the WHITE preset to where the camera tilts up into the fog above the Golden Gate Bridge.

To do this, drag the WHITE present to the beginning of the clip 

Perhaps it could be longer with this transition still selected in the sequence.

Select the yellow transition on the timeline and drag the slider to the right to extend the duration. You can also enter a numeric value.

Type 2 and press return to make this dip to white take exactly 2 seconds.

To transition on the cyclist's motion right into the next clip so it feels like we're seeing her POV (point of view) over the handlebars as she continues to ride onto the bridge.

Drag and drop a cross dissolve preset onto this cut and play through it.

Press the equal sign to zoom in.

Now we can click on the center of the transition and drag it left or right, so the effect will begin and end earlier or later as it blends the two clips together.

If we drag the transition to the right of the cut, it doesn't really work because you can see the cyclist slowing down and coming to a stop.

But if we drag the transition to the left so it ends at the cut point, the incoming clip will be fully visible before her bike comes to a stop, creating the illusion that she's still in motion and now riding on the bridge.