Floor Press
The floor press is the best way to start working up to a bench press. Not only is this an option if you don't have a bench, but it's a safe way to begin to train the movement, especially if you have any past shoulder injuries.
A video link is provided below detailing how to initially set up your dumbbells for the press. I recommend beginning with light dumbbells (DBs) or kettlebells (KBs) that won't be difficult to lift into the starting position for the press.
Place your DBs or KBs on the floor on either side of where you will lay. You will want them at either side of your waist. Bend your knees and keep your feet flat against the floor. Grasp the DBs and bend your elbows 90 degrees, raising the DBs with both elbows still against the floor. Press your shoulder blades together and squeeze your glutes while straightening your arms and raising the DBs at your sides. Slowly lower your elbows back to the ground. Repeat this movement for the desired number of reps.
Look for this movement in Wednesday's workout. Refer to the link below for further clarification.