Welcome aboard.
I suggest you read through this thread first as it covers much of the same ground and more 
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Beginner questions - Support - Xert Community Forum (xertonline.com)
Challenge ATP assumes you have established a good base and wish to work on a specific focus duration for 30 days.
Use the Freshness Feedback slider if calculated form doesn’t match how you feel day to day. Normally neutral (0) works for most when their signature is dialed in and training load feels about right. However, Xert doesn’t know your physiology and metabolism. Some days you may not be up to the recommendations (slide to left) or one day you feel unusually fresh (slide to right or consider a BT workout).
No need to populate the Planner a week in advance especially if you will vary your TL week to week. Most of us do not populate the Planner unless we have specific workouts we want to do next week. Even if added you can always change your mind at the last minute and your planned workout will disappear by next day (no need to delete it).
XATA defaults to what you did recently on same day of week, but you can and should change Duration dropdown if you have more or less time to train today.
You are in charge of taking rest days. If you they are same day(s) of the week, XATA will recognize that pattern moving forward. Or you can change your training load distribution week to week depending on your schedule and interpret surplus/deficit in respect to the pacer needle position. For example, if you normally ride 90 minutes on Wednesday but this week you can only ride 45 minutes and you plan to ride longer on Friday, then the deficit number today doesn’t matter much since you’ll bring the needle back up later this week. Your main goal is to keep the needle in the 11am-1pm position week to week to maintain the ramp rate goal you’ve set. The needle can dip left or right of 12 o’clock (0 deficit/surplus) and you are doing fine.
XSS per hour is where it’s at in terms of quantifying strain (low/high/peak). The harder the ride/workout the more XSS accumulated. Go deep during and XSS shoots up accordingly.
Indoor workouts will always be more efficient since you are pedaling under constant strain (ERG control) versus intermittent and variable nature of pedaling outdoors.
Dance with the Devil is a 3 or 3.5 diamond workout of about 92 XSS/hour (Difficult rating) while the outdoor ride was around 69 XSS/hour (Moderate rating).
Workout variety expands as you move into 3 stars territory, but your ATP setting is limiting choices to endurance when yellow and near Rouleur focus when blue/green.
You can also add more workouts by joining the Basic Workouts Library. If you decide to do that but prefer SMART workouts (curated by Xert) you can use Filter to exclude Community shared workouts from recommended lists.
Xert is hybrid polarized by default but you can steer it into whatever direction you want by the selections you make day to day. You can also use dislike/like over time to create your own preferred workout list.
Reference –
Sweet Spot, Threshold and Polarized Training … By the Numbers – Xert (baronbiosys.com)