You’re mostly over reacting. You’re on the first few days, months, or year at this work environment, you’re not going to feel plugged in to it by yourself or coworkers right off the bat. You’re also making the mistake a lot of people make in any interpersonal interaction, you had one good interaction, and you didn’t get reciprocated treatment, so you assume it’s not working. One interaction isn’t enough, you need many, 10-12 interactions are more realistic. Your new, so the burden is on you to provide the majority of the interaction.
You aren’t wrong AT ALL about not going out of your way to interact with people who seem distant, or standoffish with you. Not being forceful with interactions shows respect and intelligence. Go for natural interactions and remember, you’re a dozen more interactions away from even seeing if this is working. At the same time focusing on people who are friendly and open to you is a wise choice, some people won’t warm up to you until you have established connections in their workplace.
Also as an introvert that worked in sales for a long time, you’re not understanding what introvert means, or maybe the way you’re talking about it is awkward to me. Introverts make great sales people, I can talk to an introvert on day one and say ''when you’re asking if they want the service package, you have to explain all service after purchase is 100% free, and includes a regular yearly maintenence service, and all can be in home service, they think it’s an extended warranty if you don’t explain it’s a service package" and they will get all points across every pitch, and typically they will focus on word choice and reading customers. Extroverts? It’s at least three conversations about this, and I have to coach their word choices.
Introvert just means you’re exhausted by socially interacting with others, it doesn’t mean you bad at it, or you fear it, it mostly means you’re not having fun when your talking to someone, you’re working. Lots of benefits in that, and lots of draw backs, but it’s not a lack of capability in you, it’s just a skill, and like every skill you need to practice before you get good at it. Also leaving yourself stretches of no social interactions during your work day so you don’t get burned out is also a very good idea.
You’re on the right path, just be consistent, and accept it takes time to get folded in at a workplace, and never take it personal. If you’re there for more than a year and you feel like they haven’t accepted you, then there’s some serious problems at that particular workplace that are out of your control, and you might consider moving on, or location change, whatever your profession allows that’s also in your favor.