I’m currently working on a wood woad homebrew race and magic club calls for me to make clubs deal an extra 3d4 damage

You cannot have a race apply additional damage to a specific type of weapon like that. The best you can do is to add an Action to that trait to display the extra 3d4 as a rollable on the character sheet.

That’s good to know but how do I do that Thanks in advance 

1. Open the racial trait in the homebrewer. (If you have not done so already, type a short version of the description into the snippet field and [SAVE]. Then, open the trait again.)
2. Highlight the snippet entry and Copy it.
3. Scroll down a little to the Actions section of the trait, expand it and click the big blue button that says [ADD ACTION].
4. Choose “General” as the action type.
5. Fill out the form exactly as I tell you to, do not fill in anything else. Okay?
   • Give the Action the same name as the racial trait
   • Set the dice count to 3
   • Set the die type to d4
   • Set the damage type to “bludgeoning”
   • Set “display as attack” to yes
   • Set the “activation type” to special
   • Paste the snippet from the feature into the snippet field for the Action so they both say the same thing
   • [SAVE] the Action, then [SAVE] it again.
6. Click [SAVE CHANGES] for the racial trait, and then click [SAVE CHANGES] again for the whole race underneath Basic Information.

Congratulations, you will have just programmed your first Action.

Thanks so much this is incredibly helpful 

Happy to help.