They sound like fun projects, but they are not really practical.
Both require parts that would be hard to find. They would also cost a lot more to make than the commercial versions, even if you could get the parts.
Even if you did make a phone, it would be illegal in most countries to connect it to the telephone network without getting it approved, and this is very expensive.
You can buy MP3 players for a few dollars on Ebay and these have LCD displays and good sound. I have one that holds 4 GB of songs. It plays video. It works as an FM radio. And it cost about $10. How could you compete with that?
Better projects that you will be able to use in the future would be a variable voltage, regulated power supply or a radio frequency signal generator or an audio frequency signal generator.
First, though, you need to buy a digital multimeter.