- Basic manners - like you say, not excluding you, greeting you, making you feel welcome in a group...moving aside so you can sit down.
If you say something, making eye contact and responding.
It doesn't need to be too formal, and some people can be shyer or there can be cultural differences, but you'll get a feeling for this.
- Being interested in you and engaging with you when you talk but not overly nosy or judgemental or critical.
You don't feel like you have to beg to speak, or that anyone is going to be terse or negative or talk over you.
If you are a bit awkward or ramble on a bit, unless it's personally insulting someone, you shouldn't be called out or criticized.
Everyone has awkward moments.
People who like you won't humiliate or exclude you for it.
- Treating you well regardless of how much they can get from you....often I find people can be "overly nice" if they think they can get something from me then rapidly switch if they don't think I'm giving them anything!
(this can be anything from contacts - if they think I have posh rich friends, or creepy men who want sex).
- Like all things, this takes time and judgement and practice.
I don't think you need the person to feel like your best mate all of the time or overly gushy, but just a sense of "that went ok" so you're not worrying about things.
Stay independent (for example, don't rely on people for lifts, buy your own drinks) and see how they are over time.
People don't need to solve all your problems - that's your job ;-) - but accept you as you are.
You'll be surprised where you meet supportive people - don't judge on appearances.
- Trust your instincts.
Looking back on when I was younger, if my instincts were that I wasn't wanted in a group, or someone felt a bit off...
My instincts were generally 100% correct..I felt like shit the more I engaged with these groups and people.
There's a lot of people who say "just be more sociable" or try to make it your problem or tell you to be nicer to win them over...
But especially as a younger woman (amplified if you're ND or not white or disabled) there often is a lot of hostility or micro-aggressions that you can't control just if your face doesn't fit for some reason.
You'll see the same group or people being welcoming or responding completely differently if someone different turns up! So you don't get offered a drink...but they do...you get ignored, they don't.
It's not your fault.
It's not your job to do something to make people accept you or win them over, just accept it and detach and move on.