Is this a good work out routine and advice?

I've never really worked out before, but started a routine this week, I will stick to working out. I do 1min of cardio -skipping/jump rope Then I take a short break and continue to doing 5 press ups/ push ups (plank type), but the type you'd do on a bench in the park, but on my bed, seeing as I can't do 'real' ones yet and I don't have a mat but hard laminate floor in my room. I repeat these steps until I've worked out for 20mins. I do two days in a row, then take a one day break. I am 5'5, female and 18. Is this a good workout, I weigh between 6 and 7 stone as well. I'd like some abs. Is this achievable with my routine and weight e.t.c? I don't stretch before a work out, due to not knowing how, but I want to. What are some easy and effective stretches?