Learning to play multiple musical instruments is fun and excited, especally if you already play one instrument. Once you already understand how to read music and rhythms the rest is simply learning the specifics for that instrument. There are only two basic components you will need to learn to add a new instrument. How to produce sound and how to get the right pitches.

If it is a wind instrument producing sound will be simple in some ways. For example, all the brass instruments create sound the same way, once you learn one, you can do them all. These instruments require air to be blown into them in one fashion or another.

If it is a percussion instruments you merely need to learn the correct mechanics for hitting the instrument

If it is a string instrument, you need to learn how to get the correct pressure and drag out of the bow or how to strum correctly.

Now to get the correct pitches out of pitched instruments just requires knowing the right combination of keys or strings to press down and you should ahve it. As you learn multiple instruments int ehs ame families you will find that there are many similarites between the instruments and you will be able to add more an more instruments at a higher frequency.

Good luck and have fun :)