everything is bold, and pagebreaks are appearing in the wrong place

Question

I'm just starting trying to use texmaker 3.3.2. I think I understand the basics but already in a very short document, I have multiple problems. I just downloaded texmaker so I don't think I accidentally changed any defaults or settings.

First problem: All the text is bold unless there is other formatting that overrides it, e.g. an enumerated list or table of contents.

Second: All of the pagebreaks appear one paragraph before I inserted them.

I'm using the default settings of PdfLaTeX + View PDF but I tried some of the others, and it still happens. At first I thought my text might have a sequence of characters causing the bold, but it clearly doesn't, since I replaced it with the dummy text below and it's still happening.

\documentclass[11pt,letterpaper,titlepage]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\author{Me}
\title{My title}
\begin{document}
\maketitle
\tableofcontents
\section*{Acknowledgements}
\paragraph{I would like to thank my research advisor.}
\paragraph{And some other people. }
\paragraph{This always ends up AFTER the page break, alas.}
\pagebreak
\section*{Abstract}
\paragraph{Most of the abstract.}
\paragraph{One more thing that also appears after a pagebreak.}
\pagebreak
\section{First section}
\end{document}

Answer 1

\paragraph is not intended for setting normal text, it is a heading, on the level below subsubsection. See any introductory text, such as the wikibook or The Not So Short Introduction to LaTeX2e.

Just write normal text directly, and separate paragraphs with an empty line. Also, \newpage is usually better than \pagebreak (see comment by egreg). See \pagebreak vs \newpage for the difference between them.

\documentclass[11pt,letterpaper,titlepage]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\author{Me}
\title{My title}
\begin{document}
\maketitle
\tableofcontents
\section*{Acknowledgements}
I would like to thank my research advisor.

And some other people. 

This always ends up AFTER the page break, alas.
\newpage
\section*{Abstract}
Most of the abstract.

One more thing that also appears after a pagebreak.
\newpage
\section{First section}
\end{document}