The set of all rational points in an elliptic curve $C$ over $ℚ$ is denoted by $C(ℚ)$ and called the Mordell-Weil group, i.e.,
$C(ℚ)=\{\text{points on } $C$ \text{ with coordinates in } ℚ\}∪\{∞\}$.
1) What is the points $\{∞\}$?
2) If we ignor the torsion part of $C(ℚ)$ then what is the coordinates of $\{∞\}$?
$\infty$ is the point at infinity on the elliptic curve; its identity element. If your elliptic curve is given by an equation in Weierstrass form -- e.g. an equation like $y^2 = x^3 + Ax + B$ -- then the projective coordinates of $\infty$ are $(0 : 1 : 0)$.
If you are not familiar with projective geometry, then you need to either learn it, avoid asking the question of "where" $\infty$ is, or adopt a heuristic such as "$\infty$ is at the 'end' of every vertical line". (but you should probably learn projective coordinates sooner rather than later)