Just completed W1D1 and am feeling a bit lost on how running should feel

I'm a chronic overresearcher and probably know more about running than I'll ever need at my level (pacing, posture, heart rate zones etc.) and I know that I should repeat days or weeks if I can't finish them, but something I couldn't really find anything on was how hard or easy each session should feel to know you're getting challenged enough, but not too much.

I only know running as a warmup or punishment in school, so the only feeling I ever got from it was PAIN. The last time I ran 2 years ago was with my bf, who pushed me for 15 min of slow jogging without any exercise prior, but that also made me sore for half a week and I know that's not the intention for C25K when my next workout is supposed to be in 2 days.

So my question is, if I did those 8 intervals of 1min run and 1:30min walk, how tired should I be? If after the last interval I could still run for 2 minutes more, should I just skip the first week or should I rather try to increase my walking or jogging speed? Or do I keep this up the same and just feel glad I'm not completely winded after? (if it changes anything: my pulse was at times up to 190 but I still felt like I had a bit energy left, and now after showering I'm less winded than after my usual half hour yoga sessions)