So here is some advice from a "senior colleague". Watch what they do and learn from it. When they ask you to do something that seems like low level grunt work, do it and learn everything you can from it. Look for way to make improvements and implement them. Take ownership of whatever it is that you are assigned to do and do it well. Pay attention to all the details. Volunteer for whatever comes up no matter how meaningless it may seem to you. It probably isn't and is a valuable learning opportunity.
Get out of the office and spend time in the field and when you do, watch and learn. Take any opportunity for this. If you are in a discipline that doesn't work in the field (IT, finance, HR, etc.) go to the field anyway and meet the people that actually enable the company to make money. Ask them questions about what issues they deal with and help them to solve those issues.
There are no shortcuts. There is only one way to understand what someone with 20-30 years of experience knows. That is to have 20-30 years of experience. There are no life hacks to it. There is no "One weird trick" that you can pick up from a website.
When they tell you something isn't right it is probably for a reason. Try to figure out why. Then ask them if that is correct. Then absorb their response and try again. Repeat for 20-30 years.