If you find yourself repeating the same text over and over, Apple provides a text substitution feature in Mac OS X. On current macOS, go to Apple menu > System Settings > Keyboard > Text Replacements. Click the Add (+) button, enter a shortcut and its replacement text, then click Add and Done. Text replacements work in supported apps; where available, use Edit > Substitutions > Text Replacement to enable them in an app. The screenshot shows the older Mac OS X interface. I like to precede my shortcuts with a slash so that I don't accidentally insert a long string of text.If you need more advanced text substitution (formatting, the ability to choose items from a menu…) check out TypeIt4Me ($4.99 Mac App Store) or TextExpander ($34.95).
If you’d like a hand with this, I offer one-on-one tech tutoring in San Francisco and Washington DC, and via Zoom for anyone anywhere. Book a session, and we can go through it together at your pace.