I’ve been having problems with blocks missing. Meaning the Block is replaced with an orange “Missing”. I’ve also had issues with the character. When I go to third person my character is a 2x2 orange block.
Is this normal?
yes it is normal to be a 2x1 orange block atm (2x2 is not normal) I don’t know about the missing blocks.
The blocks that say missing are either healing blocks, embers or on some worlds there are blocks that dont have textures yet. So, yes normal 
Those are both place holder textures that will be replaced before the full release of the game. This game is still in alpha stages of development.
For an example of how the player models will look like have a look into the Devlog section in this forum. There you will see on what the devs are working on in the moment 
*Pre-Alpha