Then it seems very unlikely the graphics (especially the Nvidia GPU) are the problem. Note that by default, your laptop uses the Intel GPU to run the...
You mention Ubuntu, but not which Ubuntu product (Server? Desktop? Core?) nor which release you're using, nor if using a release that has ISO choices...
Try installing gnome-tweaks then set preferences (fonts etc.).
Also there is Settings (global in top toolbar) and separate Settings (hamburger icon)...