If your International is from the early seventies, you have a very nice riding bike. Not the top of the line to be sure, but a nicely equipped better than entry level bike.
I had one back in the day. It used Araya rims which were pretty damage prone, possibly due to the fact that I was 15 when I bought the thing. It has Suntour VGT derailleurs and Suntour Power stem shifters. It never missed a shift. I agree with Skyewalker's advice. Try it out and get comfortable with it. Don't rush into spending any money you don't need to.
I went from a late sixties vintage Raleigh Grand Prix with Simplex Prestige to the Nishiki. I had no idea a bike could shift so well. Who knew???
__________________
1971 Paramount P-13 Chrome
1973 Paramount P-15 Opaque Blue
1974 Raleigh Professional Blue Mink
1991 Waterford Paramount
Holland Titanium Dura Ace Group
Holland Titanium Ultegra Triple Group