Working in America can be tough especially for long working hours, high expectations and tough competition but every time I sent out a resume they almost always replied, even when I sent a spontaneous application. I have always received an email even just to tell me ‘Thanks for the resume but at the moment there are no open positions’.
No one puts the date of birth on the resume even if obviously a potential employer can easily trace your age through social media.
I like the job interview in America because you feel that you are there ‘as an equal’. You don't go hat in hand and with the feeling that whoever is in front of you is doing you a favor by listening to you and even more by offering you a job. It's true, you need a job but the person in front of you also needs a worker and even if he is an important company manager he does not act like God come down to earth.

At the interview, talking about salary is not taboo. You can ask even before going to the interview, at least the approximate figure they have in mind, to get an idea.
Many companies include the salary figure already on the job advertisement.
Sometimes they insert a variable figure based on experience.
In any case, during the interview you can negotiate, certainly with delicacy and with a certain margin and only when you understand that they are really willing to hire you, but it can be done. It's almost normal.
Apart from salary, elements not to be overlooked and to be asked during the interview are vacation days, and benefits such as bonuses, insurance and 401K. Each company offers, or does not offer, certain benefits.

Medical insurance is a benefit that they often include with a small sum deducted from your paycheck. Usually companies give you medical and dental services, more rarely also ophthalmology services.

The 401K is a great benefit. Not all companies offer it. It's a supplementary pension: a percentage of your salary is deducted every month and paid directly into this fund. You decide the percentage and you can always change it. For example, if you pay 3% they pay 3%, if you pay 5% they pay 5%, but if you pay 6% they always pay 5%, they don't go any further. There are also those who do not use it because they cannot or do not want to receive less pay every month but I always recommend doing so, even a small percentage helps and accumulates in the long run and then when there is a match from the company it is good to take advantage of it.

Even if you work a lot, the relationships between colleagues are cordial, friendly, it almost feels like being in the family. The superiors, the managers, and the CEO take it easy, they treat you as an equal and may easily chat with you at a coffee break.

The usual working hours are the classic 9 to 5 but it depends on the company and your role. Overtime is generally paid and it is normally paid 1.5 the normal hourly rate.
Working in America is generally at will, which means that the company can fire you overnight without a reason even if it is courtesy to give you at least two weeks notice. In some cases, however, they can really send you home suddenly, usually for serious reasons, and you don't even finish the day, you take your things, put them back in the classic box you see in movies, and leave. However, the same thing applies to the employee who can leave overnight without notice, but even in this case it is courtesy to give at least a couple of weeks notice.