Check first on a smith chart whether transmission line that you can easily make or get and adjust its length has proper impedance for both source and antenna. The shorter length matching section has, the wider bandwidth you’ll get. There are typically two solutions, of which one is better. Ideally you’d like to have transmission line impedance a bit lower than what would be needed if only transmission line part was used (without stub)

If you want to make a yagi, or mount antenna close to a mast and don’t care particularly hard about extremely uniform coverage, you can modify impedance by changing distance to reflector. If you want to use something like this www.wa5vjb.com/yagi-pdf/cheapyagi.pdf then this antenna (radiating element) is already unbalanced and doesn’t need balun that badly