Making fonts is hard. There are plenty of online places for people who make them*. FontForge is free and very powerful, but with that power comes a whole lot of confusing menus and options. Michael Harmon on YouTube has some
tutorials for it. There's also the
official docs, which i think do an alright job for how much there is to cover.
My process every time i've tried to start one is to draw glyphs†, either on paper or in Inkscape. SVG files from Inkscape can be imported into FontForge, i find the former's editor a lot easier to use. You can also import background images as a reference.
Since you want a font based on your handwriting, what i suggest doing is writing lines on paper (or whatever medium makes your handwriting look best) then scanning that paper and tracing the best looking letters in Inkscape. Make sure you include every character that you want your font to have. So the whole alphabet in both cases (assuming you want a font for English), punctuation marks, numerals, and symbols like the ampersand. Pangrams‡ are one way to make sure you at least have the full alphabet.
If you want it to not just be based on your handwriting but actually look handwritten, you'll want several glyphs for each letter and you'll have to set up the font to replace the standard forms with other ones based on context in a way that looks random. Like was done by
this guy.
I've never made a pixel (or bitmap) font.
FontForge does support bitmap fonts.
* Reddit has r/fontforge, fonts, typography, and neography. Probably more too.
Lemmy also has some.
† A glyph is a single appearance of a character. "a" and "b" are different letters and different glyphs. "f" and "F" are the same letter but different characters and different glyphs, though you could make a font where they share the same glyph. And ligatures are an example of one character having multiple glyphs. The I in "fi" might look different than when it's not next to an F in a font that has a separate glyph for that combination of characters.
‡ A pangram is a sentence with every letter of the alphabet in it. Some English examples are "the quick brown fox jumps over the lazy dog" and "sphinx of blæckeſt quartz, doþ ðou judge my vow riȝtly?"