I would suggest waiting until you have moved, and then planting bulbs that will grow and blossom this year. Lilies and gladiolas would probably work, and they will be perennial, so once you have them planted, you can enjoy them every year.
Also, rather than trying to start something from seed this late in the year, you might want to just go to the store and buy some. My favorite is Lowes, since they always have plants on closeout that you can gt for next to nothing, and are affordable on about anyonee's budget.
I got those bautiful $15 Knockout Roses on clearance at Lowes for $5 each.
Usually by the end of June, many places are marking down their plants to geet them sold, so you can even find tomatoes and other veggies if you want to grow some of those this year, too.