Do you want to learn proper weight lifting, programmed by a professional? If so, there are two online trainers I'd recommend - I'm not paid by either of them, but I've used their content and it's good (I'm not a PT, but I've trained now for 8 years with an excellent PT and learned a lot about what's good for my body).
Have a look at MegSquats. She offers a paid-for (about £80 a year) app called Stronger by the Day, with regular programming changes. She runs the programme herself, and you can see this on her YouTube channel.
She offers a FREE programme called "Before the Barbell". Her aim is to get a barbell into every woman's hands, and her stuff is really top notch. There's a FaceBook and Discord community for paying subscribers. I use her programming when I'm travelling for work (I'm often away for a month at a time) & away from my PT
I would also recommend you look at Rachel Henley on Instagram. Warning: she swears a lot, but she's funny. And also very serious at helping people begin their "fitness journey". I think she'll also send you a standard free programme, and then there are various levels of paid-for coaching online, including one-to-one stuff. I've not used that, but going by her Instagram form & content, she's very good. I think she's HenleyFitness on Insta and based in the UK.
I also really like Shiv Wilson's Insta content, which is solid, but I don't have any experience of her coaching.
Both MegSquats and HenleyFitness offer progressive programming so you get consistent training programmed over "blocks" or "macrocycles" of 8-12 weeks. You follow a daily workout, and can choose the intensity etc yourself. It's not random "pick this work out today" sort of stuff. It's planned and programmed.
For mobility, I think Yoga with Adriene is excellent beginner mobility stuff.