How do I remind myself to be conscious about exercising?

The best thing is to not think about it too much, take your time, and do what you can. If you need to do modifications, that is 100% OK! You're still getting your body going and building up to more advance techniques. Be mindful of your breath, your form, and contraction of muscles. Example, when doing push ups, breath in when your on the ground, when you push yourself up breath out and feel the muscles squeeze. Keep squeezing them. That's how you make them stronger and exercises get easier. That's it.