Can I Retrieve Old Text Messages Off A Sim Card?

That depends on whether or not your phone has the option to save messages on a SIM card for retrieval anytime in the future. Most phones are equipped with this sort of function, though nowadays phones no longer do so automatically as it has become more convenient to store messages in phone memory instead. Take note that SIM cards have limited memory and may thus store only a certain number of messages before their utmost capacity is reached. The last time I set my phone to save messages on my SIM card I was only able to store a hundred or so messages before it started to blink "Memory Full."