To make a very long story short, I am an adul catholic convert being baptized RO in my moms hometown but never attending a service. My mom is getting older and starting to consider going back to church. There happens to be a small Russian Orthodox church near her house but the priest terrifies her

(she is elderly and quirky) there is also a large Greek Orthodox church a little further away. My first question is how similar are these churches, do you think she will feel out of place?
My second question is in the Orthodox faith do you believe in the true presence in the Eucharist? If she goes back to church will she have to go to confession. She doesn’t think so she thinks everyone can take communion and it doesn’t matter if you are in mortal sin.
Can someone please enlighten me???
thank you!
Thank you for what you are doing to assist your mom in returning to Orthodoxy.
Do you know if the Russian Orthodox priest is married? If so maybe his wife would be more approachable and could assist in connecting your mom there. Or are there any Russian Orthodox monastics “near” you. Even if it were a bit of a distance they maybe also could help with her reconnecting with the Russian Orthodox Church.
If you visit the Greek Orthodox and find it friendly maybe you could try bringing her there. There is so much variation. The Greek Cathedral here has always been welcoming to me, a Catholic, but most of the service is still in Greek.
You might try posting on Byzcath Forum with your location and seeing if anyone there knows clergy in your area who could be helpful.
Your mother can go to confession and receive Eucharist in a Catholic Church, from the Catholic perspective, but really not from the Orthodox perspective, as Cavaradossi has said, especially since there actually are Orthodox Churches in your vicinity. Still
an Eastern Catholic priest might assist her in understanding the need for confession and perhaps clarify for her what confession would entail. Sharing the same spirituality and praxis as the Orthodox he would “speak her language” better than would a priest of the Latin Church, I think. She may have had very little and perhaps not very good catechesis is her life in the Church years ago.
You mention that you are now Catholic. That would make you canonically a Russian Catholic since your Baptism and Chrismation was in the Russian Orthodox Church

no matter if you made your profession of faith and confession in a Latin/Roman Catholic parish or some other Eastern Catholic Church. Unfortunately there are only four of our Russian Catholic parishes in the US. If you were near one the priest or deacon there might be able to be helpful.
Here we are in Bright Week with all the riches of Pascha. What a great time to be helping your mom with this! May God bless you in your efforts.