I haven't worked out in a couple of years, how slow should i start to be safe and feel good? minutes per day x week?

Good question: So long as you're healthy, try to do initially cardio exercise on a treadmill or bicycle or swim for 30 minutes 3 x a week, Then go up every week by 15 minutes so you do one hour 3-4 x a week. After a month, try adding some mild weights but do get a trainer when it comes to heavier weights, eg, benches.

Seriously....: If being safe is the major concern, then you should engage the assistance of an experienced trainer. It may seem a little too much, but without knowing your current physiological state, it's the safest way to start. You current health status will dictate as to what type, how long and and what speed you should participate. You need to control the amount of stress or it will control you.