When coming from a blue-collar background/work experience, how can I
prevent employers from making judgments about my skill based on my
Employers do tend to typecast people. If you are an automotive technician there is the potential to get stuck with the label. If you're used to using high tech diagnostic equipment this should be made clear (including naming the models you used, and what you used them on). If you were also helpful in keeping the shop computers working, point that out.
One of my personal rules about auto techs runs something like this: if the tech is driving a late model US econobox this is less good than if they are driving around a hopped up 1960s monster that they work on themselves. The latter suggests an enthusiast - someone really into cars. If this is what you are, it can't hurt to say so. There are lots of car people in big companies. Of course, they might want you to fix theirs, which is another matter.
If you're in some role that involves handling money, such as a club or church or advocacy organization, this will draw people's attention away from the car stuff. The question then becomes what you're doing in the community, not what you're doing for a living.
Most likely your job pursuit is scattershot - send it out and see what bites.
I am aware of a large research group that tests motor oils. They've been around for decades, they have massive computer instrumentation on their test stands, and they collect gigabytes of data per day. Your opportunities with such an employer are far superior to a bank or social media company.
Automotive companies have been setting up software development centers in various cities around the US. Some of these are mired in company politics and may not produce much of value, but those that are well managed would probably look at someone with a technician background with particular interest.
Anyone with heavy machinery, including railroads, mines, construction equipment, ships, and aircraft are probably interested in the perspective you bring to the table. Stockbrokerages - probably less so.
In short, you need to leverage the current and future occupational interests in combination. Consider the possibility of relocating, although you probably won't have to move far.
While you may or may not be interested in getting into search engines or finance, you can use the first job to focus on the topics you intend to pursue later. Most mechanics that I know however are 'thing' people and like dealing with physicalities. If you sit in the lotus position on a mountaintop for entire weekends then you might be into abstraction. In that case, work on programming language compilers.