Take the game at your own pace
Try not to feel overwhelmed by the amount of "things" in the game
Take regular breaks (don't go gaming for 6 hours straight without having a break)
Use the wiki and YouTube videos as a source of information.
Watch some let's plays to become familiar with the mechanics, and for tips and tricks.
I recommend Chippygaming & PythonGB, there are of course other content creators with Terraria let's play series, the 2 I listed are just my personal go to's for let's plays.
If you get stuck, don't be afraid to ask for help on the forums.
Most of all, just enjoy yourself