assuming you’re not in some weirdly abnormal circumstances (crypto?), it’s pretty simple to download a form 1040 and the instruction booklet. For the cost of printing it out and mailing it (at most a few bucks,)

as for paying the taxes, it’s generally better for you if you work something out with the IRS (a playment plan, etc,) rather than letting them do the collections route. They may have free tax advice on that matter as well.