You can control the citestyle and bibstyle separately. So it is theoretically possible to have citestyle=numeric-comp and bibstyle=apa.
There are a few caveats, though
apa needs the Biber backend, so you need to switch from backend=bibtex to backend=biber and need to run Biber instead of BibTeX (Biblatex with Biber: Configuring my editor to avoid undefined citations)
The bibliography environment will not be numbered if you only load bibstyle=apa, so you also need to load numeric.bbx again. Below this is done with
\makeatletter
\RequireBibliographyStyle{numeric}
\makeatother
It is not recommended to mix the highly specialised biblatex-apa style with different styles.
Then
\documentclass[british]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{babel}
\usepackage{csquotes}
\usepackage[%
backend=biber
,bibstyle=apa
,citestyle=numeric-comp
,sorting=none
,sortcites=true
,block=none
]{biblatex}
\makeatletter
\RequireBibliographyStyle{numeric}
\makeatother
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@misc{wordnet,
title = {WordNet: A Lexical Database for English},
url = {https://wordnet.princeton.edu/},
urldate = {2018-02-24},
author = {author not named},
}
\end{filecontents}
\addbibresource{\jobname.bib}
\addbibresource{biblatex-examples.bib}
\begin{document}
\cite{sigfridsson,wordnet}
\printbibliography
\end{document}
gives you
![[1] Sigfridsson, E. & Ryde, U. (1998). Comparison of methods for deriving atomic charges from the electrostatic potential and moments. Journal of Computational Chemistry, 19(4), 377–395. doi:10.1002/(SICI)1096-987X(199803)19:4<377::AID-JCC1>3.0.CO;2-P//[2] author not named. (n.d.). Wordnet: A lexical database for english. Retrieved February 24, 2018, from https://wordnet.princeton.edu/](../../images/0f1c6a147fef091a18cc7cc06cdff9e4.webp)
Maybe it would be enough for you to combine numeric-comp with the standard authoryear bibstyle as in Combining style numeric with style authoryear in BibLaTeX. In that case you could continue using BibTeX, even though I would recommend you switch to Biber anyway.
\documentclass[british]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{babel}
\usepackage{csquotes}
\usepackage[%
backend=bibtex
,bibstyle=authoryear
,citestyle=numeric-comp
,sorting=none
,sortcites=true
,block=none
]{biblatex}
\makeatletter
\RequireBibliographyStyle{numeric}
\makeatother
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@misc{wordnet,
title = {WordNet: A Lexical Database for English},
url = {https://wordnet.princeton.edu/},
urldate = {2018-02-24},
author = {author not named},
}
\end{filecontents}
\addbibresource{\jobname.bib}
\addbibresource{biblatex-examples.bib}
\begin{document}
\cite{sigfridsson,wordnet}
\printbibliography
\end{document}
The urldate issue is caused by a misformatted date: All dates must be given in YYYY-MM-DD format and so 2018-24-02 is not a valid date. The 24 February 2018 is 2018-02-24.
Also, it would be easier for people to help you if you could post a Minimal Working Example.
– jessexknight Mar 13 '19 at 14:59