Bash script with loop

I need in simple bash script. ubuntu requirements: 1. loop 2. each cycle. check cpu and memory if it free more than 30% (in variable) next else wait 3 load next string from 1st file. if file finished. close script 4 load next string from 2nd file. if file finished start from first line eg: not two loops but one loop bylines from 1st file and add line from second file 5. load python script in another thread with 2 param. 1 - line from 1st file. 2 - line from 2nd file. and some additional info 6. !!! do not wait until script is stopped but immediately go to point 1 7. output some info. cpu, ram, percent of 1st file, time