Please Explain me 1 and 2 with proper explanation. Thank you!

1. Eight equal charges q are located at the corners of a cube of side s. Find the electric potential at one corner, taking zero potential to be infinitely far away. 2. Four point charges are fixed at the corners of a square centered at the origin, as shown in Fig. 1. The length of each side of the square is 2a. The charges are located as follows: +q is at (-a, ta), +2q is at (ta, ta), -3q is at (+a, -a), and +6q is at (-a, -a). A fifth particle that has a mass m and a charge +q is placed at the origin and released from rest. Find its speed when it is a very far from the origin