How are classical games against ungraded players calculated?

I recently started playing classical games over the board. This is within the “Chess Scotland” governing body, if relevant.
I am ungraded. I defeated my first opponent last week who was also ungraded, with only one previous game (a loss to a 1468).
Today, I defeated my second opponent, who again is ungraded with only one previous game (a loss to a 1324).
I’m trying to establish a grading as soon as possible. Having only ever played online, I recently joined a local club, but until I get an established rating, I’m naturally being paired with other ungraded opponents within their local league circuit. I need at least 5 rated games to establish a rating, but I’m wondering if I play 3 more games against ungraded opponents, even though all 5 games are "rated" will I need to keep going until I play 5 "graded" opponents?
For efficiencies sake, It’d be good to know if I should be declining games vs ungraded players and proactively seeking graded opponents only.

Furthermore, if I successfully defeat 5 opponents in a row to establish a grading, if I do not lose or draw, how is the initial rating determined? Is it the average of your opponents rating +400, or some other method?

1. If you play ungraded people, when they get graded, you will get rating based on that

2. You shouldn't decline OTB games

That is not accurate for FIDE. Games against unrated players do not count for anything and they don't get retroactively changed.

sorry my bad

Im in USCF idk how FIDE does it

Yeah, for US Chess, unrated players get rated during their first event and there's a mechanism to initialize ratings. So if any games are played, a rating is received.

For FIDE that's not true and it's possible to play a lot of events and never get a rating.

How long does it typically take to get a rating?

For which organization?

FIDE

Re: 2 - I'm not suggesting abandoning a scheduled game. In the local leagues I'm playing in - I'm typically asked by my club if I'd like to play in an upcoming club vs club match before it's actually scheduled. It looks like in the interest of efficiency, I should only really be playing if I know the opposition is already graded (only reason I'm playing OTB in the first place is to get a grade).