I was just diagnosed with mild venous insufficiency ( it started less than a week ago). is there a general compression level that i can start with?

Start with a : Very old compression stocking of 20-30

Compression stocking: Start compression at 20-30 mmHg. If not tolerated, can reduce to 15-20mmHg.

Venous insufficiency: it all depends on symptoms, and physical appearance of the skin of the calf evaluation with venous doppler ultrasound is keyed treatment is better than relying on stockings life long very often the issue can be easily treated using laser and surgery not required see a vascular surgeon specializing in vein disease

Venous insufficiency: The best pressure for beginning support hose treatment would be 20-30mmHg pressure. If this is not enough then you can increase to 30 to 40 but for early venous insufficiency, 20-30 should be adequate.