If you are struggling with audio quality issues due to your surroundings, try:
Intro and outro music can help make your podcast more appealing to listen to and sound more professional when edited together.
When searching for music online, there will be lots of "free music" sites to choose from. However, you must always check the site's usage policies to ensure you have the relevant rights to use their music.
Some sites will prohibit you from using their music in podcasts, even though they allow usage in advertising and vlogs. This information can usually be found on a site's FAQ or "Licensing" page.
SilvermanSoundStudios and PurplePlanet both allow their music to be used in podcasts and are a good place to start when looking for your theme. It's worth keeping a screenshot or PDF of their usage policy for your own records when downloading a track.
You must also ensure that you credit the creators. Most sites will include notes on how to properly credit them in your podcast. If they don't, it's best practice to verbally include the artist's name, track title and website at the end of your podcast, as well as written in the media description on MediaSpace.