I also recommend an electrician. One of the comments indicated to make sure both of the "HOT" wires to your two new outlets are on the same phase. Your stove ran on "220/240 Volt" which means that, in the United States, the two "HOT" wires are just 120V that are out of phase. When you wire these to the stove, the stove uses both 120V in a push/pull configuration. You really should have an electrician do the work because you want either one single 20A breaker with both "HOT" wires leading out of that. Or you could install two 20A single that are BOTH ON THE SAME PHASE to connect to your two "HOT" wires of your romes 10/3. However, there are definitely electrical codes to follow and I'm not sure of this particular configuration. So, again, I highly recommend an electrician do the work and discuss the options with you.
Help with DIY dedicated circuit
I am wanting to install a dedicated circuit for my amp, but getting from my panel to the wall behind my amp is going to be difficult. As I was investigating in my attic, I realized that when I changed my stove from electric to gas, the unused 30 amp Romex 10/3 wire will reach within 15 feet of where I want the wall outlet. Do I install a junction box and run Romex 10/2 to the new wall outlet and use the 30 amp breaker? What is the best way to connect the wires in the junction box?