No crank no start?

Problem started when I replaced my battery in April 2022 because the other one was bad and replaced it in March 2020. It was replaced, but the voltmeter wasn't center and asked about it was told to just drive it. Had a lot of no starts, but used another key to do it and started, but about a week ago I went out to check the battery just in case, and they told me that everything was okay, but told it to another advance parts, but it cut out one block from there. Used a booster Pack to try and started, had to wait over 45 mins for it to restart. They told me that everything was okay, except for the alternator, which was installed this year from another place, drove it home okay, but after parking, I couldn't start it at all. Tried the booster pack to start it nothing tried hooking it to the battery still no start. I'm thinking now it's the alternator. Do I need to try to start it with some booster cables? When I hook it to the positive pole on top I'm getting some power to my antenna, radio, dome lights, but that's it, my power windows can't go up? Is the alternator gone or again could I try to start it with booster cables?