Arms are naturally weaker than your stronger, bigger muscular legs. For home workouts, my advice is to either get those ‘power blocks’ where you can change the weights with just one set of dumbbells, OR start out with a pair of moderately heavy 5 lbs weights, a pair of 10 lbs, and a pair of 20 lbs. And make sure you invest in heavier dumbbells to support your progress along the way.
Another way to add more weight is to buy a weight vest. If you do, go for one with 20-30 lbs of additional weight. Excellent for deadlifts, squats, pushups, and lunges!
To make your bench is turned into an incline or decline bench, elevate one end by putting the legs on a few sturdy books or a box. Some of the programs also require a pull-up bar.