dear bhai welcome on car care thread and ur intrest in detailing things
orbital polisher is just good for liquied glazes and waxes applicatopn and its useless for colour correction ( means removing swirls and secratches ) to me car seems re-painted and its true than ur car need proffesional assistance for sanding / compounding/ polishing/wax or sealant process and rotery polisher highly recommended for compounding / polishing
if u wish diy than start from least aggressive product thats any good swirl / secratch remover like meguair's secratch x or turtle swirls and secratch remover and any synthetic wax i.e mother synwax fx, meguair nxt or turtle ice polish
always wash car with car shampoo and use microfibers for washing/ drying/ buffing wax