Break the line in Latex

Question

I want to write a sentence in Latex but since it is too long at a point the lines breaks and it continues at the line below.

It is like that:

Which command can we use so that when the sentence continues at the second line it begins under "Hello" and not the beginning of the line?

PS: Before this proposition, there shouldn't be a number... How can this be done?

It looks like that:

Isn't it possible to put Για (the first word of the proposition ) at the same point of the second line as the point from the first line where the title begins?

I wrote the following to get this:

\Large \textbf{Πρόταση 1 } \par Για τον δακτύλιο των ακεραίων  \textlatin{p}-αδικών αριθμών $\mathbb{Z}_p, p \in \mathbb{P}$ ισχύουν τα εξής: 

Answer 1

If you know what should be on the page, you can print a line of letters (or rather pixels) from the upper left corner to the lower left corner, step to the right, print pixels downwards, step to the right, print pixels downwards .... till the page is typeset. Crappy for a human being. Humans like more structure. You have given us a screenshot of the pixel-approach (a quite blurry one i might add) and ask us to reproduce it. What is important for us to know is the structure. You want to print objects, lets call them proposition and want automatic numbering, maybe refer to them later by \ref{prop:daktulio} and want to be flexible to alter the visual appearance at one global point.
Define a new environment for that. Or use one the many theorem packages, that is fine as well.

But don't do it by hand every time.

\documentclass{article}
\newcounter{prop}
%\newcommand{\theprop}{\arabic{proposition}}
\newenvironment{prop}{\refstepcounter{prop}{\par\addvspace{\baselineskip}\Large\noindent\bfseries Proposition
\theprop}\par\noindent\ignorespaces\begingroup\color{blue}}{\endgroup\par\addvspace{\baselineskip}}
\usepackage{blindtext}
\usepackage{xcolor}
\begin{document}
\blindtext
\begin{prop}
\blindtext
\label{prop:daktulio}
\end{prop}
\blindtext\color{blue} as we have seen in proposition \ref{prop:daktulio}
\end{document}

So, to finally answer your question, i think you are looking for \noindent. But if i one day see a \noindent in between begin{document \end{document} you have to explain yourself.

Don't waste time doing the task by hand over and over again, if you can automate it within two minutes.