There are many at RG with great experience in pcr so it might be worthwhile questioning as you progress. Assuming that you mean ordinary end point pcr early steps are assessing the amplimer to get an appropriate amplimer size...for instance if it needs sequencing then define your important region and add at least 60 bases at each end to accommodate the primer and the poorly sequenced start bases. Alternatively if the pcr is to separate CA repeats tnen make the amplimer small...less than 100 bases in order to see a difference in amplimer sizes. Primers should be designed using primer 3 or primer blast

https://www.genscript.com/tools/pcr-primers-designer

https://www.ncbi.nlm.nih.gov/tools/primer-blast/

primer3 https://bioinfo.ut.ee/primer3/

to design primers annealing at 60c and having annealing temperatures close to each other

Decide which polymerase to use....cloning may need hi fidelity but amplimer detection prbably any cheap taq will do

With good clean dna and well designed primers pcr generally works well