Beginner to online chess questions about site

I'm interested in starting to play online chess. I'm not great. It's a casual hobby. I've been playing for about a decade in local clubs and tournaments. I have a rating that stays about 1350 in live games. Since COVID I've been on another site for about a month and I have gotten my rating there to just under 1400. I had heard your online rating should be higher, so that made sense. 

But I just started on here, and I can't seem to beat most players rated less than 800. I'm wondering what a score on chess.com means compared to a live score. I've faced 3 players today who were able to completely refute my best, most practiced openings. Not just beat me. I'm used to losing, believe me. I am a blunder king. I mean they immobilized my every move with crushing retorts in ways that I've only encounter playing 1800+ rated players. I can understand getting beat, but I can't understand why their ratings are so low. To me a u800 level player has just learned how to coordinate pieces.

I'm new to online chess, and I'm pushing 40 here so I'm just trying to figure out how things work around here.

Thanks

What are you rated 1350 in. I can tell you that 1400 on one particular site is like 1000 here. The ratings are super inflated there.

Standard. I've never played much blitz. I feel I'm too old to start.

That's all I needed to know. It just feels weird to go against someone with a 725 and get beat so badly. But I've also won, and I wonder if they think the same about me since I'm also rated u800 I think.

I'll find my groove. Thanks. I can't wait til this covid is over and I can play live again though.