There is SO much involved with even getting a gearbox out of a car - even before you open the gearbox itself on the bench.............if you have never worked on a car, this is absolutely NOT the place to start to learn.
A very long, involved and difficult job, especially without a proper vehicle lift, transmission jacks etc. There are so many peripherals such as exhaust, wheel hubs and drive shafts to remove, and some of those will be seized or rusted, so bolts might shear or round off etc, and will need torque wrenches to rebuild .........really, don't go there.
Honestly, DO NOT even start this project. Without any experience, or knowledge, it will not be successful and you will end up with a car on the driveway for ages. Even if you decide halfway to put it all back together to sell it, I doubt that will be successful either. To do a job like this, you need years of experience behind you.
I taught myself from around 10 years of age, starting with fixing my pushbike and then taking lawnmowers apart to see how they worked. That gave me a grounding in nuts and bolts - literally - and I built on my knowledge from there. I have removed and replaced clutches and gearboxes and rebuilt engines, but even with all my experience, I would not attempt anything like this unless I had a garage and a proper vehicle lift. Trying to do this outside, or even inside on a garage floor - lying under a car on axle stands or wooden blocks and with no experience, it's honestly not sensibly achievable.
Instead, make a cup of tea and watch someone else: Have a look online for 'South Main Auto Repair LLC'. Eric Obrochta is a guy with an auto repair business in the USA. He makes really superb videos, and is very good at explaining his thought processes and demonstrating his skills and years and years of experience. Click on 'Videos' and choose a gearbox removal video to see what is involved and what tools are required even for a very experienced professional. He tackles everything from simple brake pad replacement to complex computer and wiring issues.
Eric has recently had dental treatment, so in his most recent videos, he is having difficulty speaking (!), but chose a video from last year or before and enjoy !
PS, at the end when Eric says "If I can do it, you can do it", he doesn't really mean that, he is just being polite.