I have a curve of genus zero:
$$C: 2 x^5-4 x^3 y+x^2 y+2 x y^3+2 x y^2+y^5$$
or in homogenized form:
$$C': 2 x^5-4 x^3 y z+x^2 y z^2+2 x y^3 z+2 x y^2 z^2+y^5$$
How to transform it to some conic section curve with rational substitutions $x\to f_1(u, v), y\to f_2(u, v)$?
(or do you know Sagemath code that would do that?)
I computed singular points of the curve and also rational parametrization of the curve if that can be useful to find the transformation.
Singular points: $$(-1:1:1), (0:0:1), (\frac{1}{2}+\frac{i \sqrt{3}}{2}:-\frac{1}{2}+\frac{i \sqrt{3}}{2}:1), (\frac{1}{2}-\frac{i \sqrt{3}}{2}:-\frac{1}{2}-\frac{i \sqrt{3}}{2}:1)$$
Rational parametrization (in one parameter or in two parameters): $$x\to -\frac{p (2 p+1)}{4 p^5+1}, y\to \frac{2 p^3 (2 p+1)}{4 p^5+1}$$ $$x\to -\frac{p q^3 (2 p+q)}{4 p^5+q^5}, y\to \frac{2 p^3 q (2 p+q)}{4 p^5+q^5}$$
Also some small rational points on the curve:
$$(0,0), (-1,1), (\frac{1}{3},-\frac{2}{3}), (-\frac{3}{5},\frac{6}{5}), (-\frac{8}{9},\frac{4}{9}), (-\frac{54}{53},\frac{48}{53}), (-\frac{96}{13},\frac{108}{13})$$
UPDATE:
Here is an example of a curve of degree 3 and genus 0 that I was able to transform to conic - specifically parabola (with forward and backward transformations):
$$y^2=x^3-x^2,\left(x\to \frac{v}{u^2},y\to \frac{v}{u^3}\right)\\ v=u^2+1,\left(u\to \frac{x}{y},v\to \frac{x^3}{y^2}\right)$$
The accepted answer does not give any details of how the transformation was found, so let me give an alternative answer. First, you have a parametrisation so you have a morphism $C \to \mathbb{P}^1$. Embedding $\mathbb{P}^1$ as a conic can be done in many ways (choose three generic homogeneous degree 2 polynomials in $k[x,y]$).
Let me then deal with the more interesting case: We have a genus $0$ curve $C \subset \mathbb{P}^n$ and we don't know whether or not it has a smooth rational point. The key point to note is that if $C/k$ is a genus $0$ curve, then (by Riemann-Roch) the complete linear system of the anti-canonical divisor $|-K_C|$ defines a degree $1$ rational map $C \dashrightarrow \mathbb{P}^2$.
I don't know how to make this algorithmic in SageMath, but Magma has very good canonical divisor functionality for curves: