If they're hardy, crape myrtle would do the trick, and fast.

One of the crabapples, selected for size, color of flowers/leaves, color and persistence of fruits AND for disease resistance, might be just the thing.

Another thought might be a Japanese Maple, one of the taller ones, although that might be too much sun for a JM. Several other maples will stay small - Acer ginnala/Amur maple; A. griseum/paperbark maple; A. tatari8cum/Tatarian maple. If hardy that far north, Shantung maple might also work.

A tree lilac - if you like the scent of the flowers - would stay fairly narrow.

Amelanchier/Juneberry/service berry might eventually get too tall, but would cast a nice light shade, flower in spring, give berries the birds might share in June, and has decent fall foliage.

Carefully chosen, one of the clumping bamboos might be very nice - exotic and different. It would be evergreen.

In full sun, redbud would probably stay small enough for your wants - you have several cultivars, with varying leaf color and flower color to choose.

Fringe tree is another spring-flowering tree with good fall color - no fruit to speak of.

Smoke tree, esp. if limbed up on a selected specimen, could be very nice - again, there are several leaf and flower colors to opt from.

an awning would be the fastest ..

by the time you buy a $500 plant .... big enough to accomplish your goal ... in the near future ... you may as well have spent the money on the awning ...

ken

Ken is correct if you need shade NOW. They also make "window shades" for the outside of windows - try googling for Coolaroo, which is one brand I can remember off hand.

If you can wait while you put it up, a trellis or pergola set about 2' away from the wall, and trained with a fast growing vine would be the second place winner in the speed stakes. (Try an annual vine - lablab beans, morning glory, etc., for the first year, and clematis, rambling or climbing roses, AMERICAN wisteria, etc. as permanent vines for the later years.) A pergola with a series of narrow "laths" across its top would give immediate shade while you wait for the vines to grow, or you could cover the top with shade cloth as a temporary - or permanent - measure.