is it better to use a metronome than to play along to songs on guitar pro? do i need to learn to count the sixteenth notes, rather than just play along in guitar pro? ty.
If you have a good sense of rhythm, then you can probably get away with just playing by what you hear (and you can create some better dynamics if you're not counting strictly down to the note). However, if you start playing in time signatures like 7/8, 9/8 or 15/16 for example, then it would help a lot to be able to count it correctly. For common time, it's easy enough to just listen to the general pulse of the song and play by feeling around that, but as the music gets trickier so does the ability to just sense the rhythm and play around that. I recommend learning how to count at least 7/8, 8/8 and 9/8 properly just to avoid confusion. Then again I am guilty of just playing by feeling and using a metronome myself so I am not an expert at counting.
If you're just learning a song you like or something it's fine to play along with guitar pro, but if you start to learn complex things or if your practicing doing some sort of technique then it is best to use a metronome to keep in time and to increase your speed / effectiveness.

For example you could play along to a song you like, but if you are learning to sweep pick, it's best to use a metronome instead of playing along to a song with sweeps at first.

By the way, if you don't know already, you can mute instruments in guitar pro. Mute the instrument you are playing, it makes it better / easier IMO.