5 days a week Gym training suggestions?

I'm (43M) just starting my gym routine and was wondering about some guidelines where to get informed about good workout schedules, in example which group of muscles to do on which day for optimal effect?

E: I'm 176 cm (5 foot 9) / 86 kg (190 lb) now. Want to reach 80 kg (175 lb).

I want to lose that belly and work on overall fitness/muscle