Hi,
There may be an option to hide/show 'Additional Checkout Buttons" in your Theme Settings.
If not, go to Themes > Template Editor > cart.liquid and look for:
{% if additional_checkout_buttons %}<div class="additional-checkout-buttons"><p>- or -</p> {{ content_for_additional_checkout_buttons }}</div> {% endif %}
change that to:
{% comment %} {% if additional_checkout_buttons %}<div class="additional-checkout-buttons"><p>- or -</p> {{ content_for_additional_checkout_buttons }}</div> {% endif %} {% endcomment %}
The comment tags will stop it from rendering and you can then easily reverse the process if you ever need to.
Alternatively just delete the code rather than replace it!
Let me know if you get stuck.