Fortunately, Google Meet is one of the easier video conferencing solutions to use on the market, so this shouldn't be too difficult.
First, there's no need to download any software; just go to the Google Meet website (www.meet.google.com) to access your meeting. Once you click "New Meeting" or enter your meeting code, you'll be instructed to choose a Google account to enter with. If you don't have one, that's all right, but you will be required to request entrance to the meeting, rather than just jumping in.
Once you've done that, you'll be ready and raring to start your meeting. Just make sure your video is streaming and your microphone is unmuted, so you can actually participate.