Try reading the user-created gameplay guides on the official wiki.
https://rimworldwiki.com/wiki/Guides
Read the Progression guides and then whatever else you're having trouble with... Combat, Construction, Food Production.
Be aware that even if you lose all of your colonists, you may to choose to keep playing and after a short time someone will join your colony. Any structures that your first colonists built will be a head start for the new colonists. RimWorld is meant to be a story, and any playthrough could actually be about a group of settlers that encountered a previous colony that didn't make it.
https://rimworldwiki.com/wiki/Guides
Read the Progression guides and then whatever else you're having trouble with... Combat, Construction, Food Production.
Be aware that even if you lose all of your colonists, you may to choose to keep playing and after a short time someone will join your colony. Any structures that your first colonists built will be a head start for the new colonists. RimWorld is meant to be a story, and any playthrough could actually be about a group of settlers that encountered a previous colony that didn't make it.