An epic way the enter someone's dream is to actually dream about them first. Then take them with you to your astral sanctuary and let them lead you into theirs
The Astral Plane is just the Second among other planes, and it isn't about being at the exact same place at the same time. It is possible for two people to meet each other but there are certain conditions that allows such experience. One of which is based on the emotion of the individual. [Depending on how you were before entering the plane, it is likely you will meet other people in there aside from who you are expecting] And the thought of manipulating scenario's based on your desire is not possible on the Astral Plane.
OK so first you actually need to know lucid dreaming. Which could take a while to learn but is the main key to help you dream walk.
After you have succeeded at about 15 times or more then you can try dream walking but ONLY do this with permission from other people. If you don't have permission it's rude and intruding on their personal space... but if you can't get ahold of someone and want to use it just to make sure that they are OK then that's fine but after that you would need to get their permission to keep talking to them in their sleep
So after you have got a hold on lucid dreaming and have someone who agrees to let you inter their dreams you can start practicing.... you really need to talk to this person and try to plan conversations ahead of time to make sure that you know that it works and after each time you think that you have made contact with them in the dream it's good to talk to them sometime after you wake up to see if they saw you in the dream or else it could be your subconscious mind playing a trick on you
So to dream walk you first get a lucid dream going and once you're sure that it's a lucid dream you want to make a door appear in front of you that when you open it and walk through it takes you straight to them.... it takes a lot of practice to get it right and actually make contact with the person you are trying to talk to.
Another thing is do NOT do anything harmful to anyone in anyway in the dream it might actually hurt them. And do NOT try to control their dream unless they give you permission.
If anything is confusing and needs clarification please ask and I'll try my best to clarify myself
