There are several free online meeting apps. Some are better than others, so you are encouraged to do a little research on which one will work best for you. If you do use an online meeting app, be sure you use a password! Some platforms are more vulnerable than others and are constantly "bombed" with audio and video obscenities. Your research should include how reliable or vulnerable a platform is.
A few of the companies providing free teleconferencing include, in no particular order:
Note: Each of this has different restrictions, i.e. number of participants, time limit on meeting, etc.. Some have inexpensive "Pro" or "Plus" service plans that are relatively inexpensive (less than $20.00/month) and provide some valuable extra features.