1. The unofficial checklist by Samantha Craft
Check how many of these statements apply to you.
2. Self-assessments:
These are the self-assessments used in formal assessments by healthcare practitioners.
Here are my test results compared to the average results for autistic women. The website (button above) also details mean scores for men, non-binary individuals and neurotypical/allistic people.
3. Scientific papers
Educate yourself and identify your phenotype (observable traits). Here is a selection of scientific literature to start with.
4. Join a community
Joining an online community/forum will allow you to ask all your questions and interact with other autistics. That way you will get a better idea and find support. The sub-reddit r/aspergirls is a good place to start non-males.