What are the benefits of attending international conferences at student level Is it beneficial to attend international conferences at student level, and what are tips to follow when attending such international conferences?
It is hard to tell - it depends on the conference! 

Possible benefits (amongst others) can be:


Learning more about your field and getting more motivation for your studies
Learning about different countries and cultures
Learning how scientific conferences work
Preparing your own scientific contribution for a conference
Networking with well-known people in your field (usually there are some invited speakers)


I would strongly recommend to submit your own contribution to such a conference in order to participate fully. 

For the "tips"-section:


Hang out with people you did not know before
Find a good mixture of new / unknown topics and things which are close to your fioeld of interest
Attend every social event
Don't hesitate to talk to foreign people.