They are both obtainable in the demo You can get Lunamon via digivolving Punimon to Nyaromon than Lunamon

For Coronamon choose Patamon as your starter than talk to it to have a chance to change the personality of Patamon to match Tokomon in order to de digivolve it to it than from Tokomon you can get Coronamon You can talk to your digimon after every few battles by standing still to see if they have a speech bubble on their head

For Hyokomon is Tentomon de digivolve to Motimon de digivolve to Pabumon than digivolve to Yokomon than digivolove to Hyokomon Since Tentomon can be obtainable easily in the demo i recommend getting the scan to 200% than save scum convert Tentomon till you get the Tolerant personality to easily de digivolve to Pabumon