Enter
The kanji and the radical are the same, so remembering the meaning of this kanji is as simple as making sure you know the radical for enter first! If you know the radical, you know this kanji means enter as well.
Make sure you know those radicals, yo!
にゅう
はい, い
None
Turns out, after you enter the teepee (you'll remember that the radical is a teepee with a big entrance to it), you're given a new (にゅう) one! Now you have two teepees!
Imagine lights turning on and flashing, and an entire audience inside. You're at a gameshow, and the announcer announces the neeeeew teepee in his announcey voice. Feel the surprise. Feel the happiness. Feel the excitement. A beautiful new teepee all for you!