FOSS gamedev and creative worlds

i've been working on my mod now for about 2 weeks but have ran out of ideas to put in so i thought about making a block that changes appearance when right/left clicked (kind of like the computer mods computer screens) but do not know how to code it, could anyone help please?

Do you mean during right clicking, or after right clicking.
Only that latter is possible.

You would need to change the block from say mod:node to mod:node_2.

You could use entities like the signs mod by PA to add custom textures.

just punching once