This may call up a simply answer I dont expect, however now that im not using a TA for work. I need assistance. How do you book multiple airlines on one int?

JLN-MCI (mesa) US
MCI-CLE AA

CLE-MCI AA
MCI-JLN (mesa) US

Thanks

Also: what is the easiest way to find these kind of flights? US is only option to MCI, but once @ MCI I wish to use AA for CLE.
or airports around CLE that can make this work trip easier

AND not fly on CR7's