Total number of deaths in the USA before COVID-19 and in 2020?

The best data source for looking at total deaths in the COVID-19 era is to look at the CDC's excess deaths data. These data compare actual death data (blue) to seasonal trends (yellow), and indicates weeks for which deaths are greater than would be seasonally expected:

You'll note some peaks above expected associated with a worse than average influenza year in 2017-2018, and from COVID-19 in mid-2020.

There are some important things to consider when looking at these data, copied from text at that link, with some bold added by me:

Number of deaths reported on this page are the total number of deaths received and coded as of the date of analysis and do not represent all deaths that occurred in that period. Data are incomplete because of the lag in time between when the death occurred and when the death certificate is completed, submitted to NCHS and processed for reporting purposes. This delay can range from 1 week to 8 weeks or more, depending on the jurisdiction and cause of death.

Therefore, you should take the data on the far right of the graph in particular as likely incomplete; they will rise over time as more deaths are tallied.

Additionally, these are not purely raw deaths, but rather corrected for known sources of error in the data collection. There are also options to display the data without weighting, but these even further underestimate the more recent time points. Data through May are more complete than more recent data.