Foam in the urine can be a sign of protein present in it. However, I find that patients tend to overestimate how much foam they actually have, especially as a departure from normal. It would be important to actually quantify how much protein you have rather than relying on how much foam you detect. This can be done simply by measuring an albumin to creatinine ratio on a spot urine test.
It really depends on what is causing the disorder, how much protein in the urine, blood pressure control etc. Stage 1 kidney disease is a very broad term and the vast majority of such patients will never end up at end-stage kidney disease.