jacs, These little player a good value but they do have some draw backs. While playing music you can only access music related functions like equalizer, repeat etc. There is no way to access folders while music/video is playing.
Your firmware is like the operating system of your player the MP4 Players version of Windows. If you go to the settings menu you will find an entry called Firmware Version, here you can see what version your firmware is. It is a good idea to know what version your player has in case you have problems with your player in the future.
Although it is possible to change or upgrade the firmware on your player it is not recommended as a bad firmware upgrade can leave your player in a coma. Just look at the DEAD PLAYER forum to see how often this occurs.
The other thing you should do is make a backup copy of your firmware once again incase you have problems in the future. The good news is this is not to technical and there is a guide on how to do it HERE
The program you need to do this is s1fwx which you can download from HERE
Once you have extracted your firmware you should save it somewhere safe or better still upload it to the site, that way you will always have a backup copy and others can also download it should they need to.
Welcome to the site, there is a lot of good information here that members have contributed that will help you get the most out of your player.
If you have any more questions do not hesitate to start a new post, someone will have an answer for you.