Workout suggestions?

💙C

So this is my mid section. I weigh about 130 lbs and I’m 5’4”. My core is mushy and I don’t have much strength at all anywhere. Lately crunches are killing my back. I just need ideas for someone who doesn’t need to lose weight but is basically a beginner. I’m not strong and get tired out easily when working out. I need ideas that are easy enough to keep me motivated but hard enough to start to show results over time. I need something to build on. Most stories I see about weight lost or strength training are from people who have some strength or athletic ability. That’s just not me but I have to have some potential??