I’m not too sure how to earn my guinea pigs trust, like, it runs from my hand when I go to pick her up, she might just be timid but I just want to learn a little more about getting my guinea pig to really like me. What should I do

?
Hi and welcome!
It is great that you want to learn more to gain the trust of your little girl.
1) Guinea pigs are prey animals that live in groups. Shop piggies are commercially bred with no human interaction before they are ripped away from their group, distributed to shop branches and sold as singles into homes where they are expected to instantly function as living cuddly toys.
Your little one is currently very lost and very alone in hostile territory. Think about it from the perspective of a prey animal that has been carried off by huge smelly predators who take it out to play with from time to time, but may kill it at any moment...
Try to avoid any predatory movements and behaviours. Respect prey animal instincts and work around them to not trigger them. Be patient. Instead of expecting her to learn human language and behaviour, try to communicate in ways with her that she understands straight away. Trust is a tender plant that needs to make roots first before it can grow.
Guinea Pig Facts - A Short Overview
How Do I Settle Shy New Guinea Pigs?
Understanding Prey Animal Instincts, Guinea Pig Whispering And Cuddling Tips
How To Pick Up And Weigh Your Guinea Pig
2) As said - guinea pigs are group animals; they are not wired to be alone. They have a 24/7 need for companionship, which you as a human just cannot cover.
The VERY best thing you can do for your little girl is to get her a same sex companion to have for full time stimulation and communication. Social behaviour and interaction in guinea pigs is much more complex than expected, as recent studies have found. Do you have several hours every day for the next 5-7 years that you can devote to her needs, which just won't go away when you are busy?
Having happy and fulfilled piggies really prolongs their life/physical and mental health.
You get to enjoy the vocal interaction that makes piggies so unique and endearing without missing out on your own relationship - you just double the second aspect but don't have to worry about failing a very dependent pet if your social life, studies or job take a front seat. Watching your little girl being a happy and busy guinea pig and reaping the rewards is going to make you very happy and often chuckle or laugh, too!
Companionship
Bonding: Illustrated Dominance Behaviours And Dynamics
What to check and look out for in new guinea pigs (vet checks, sexing, parasites&illness)
All these guides are part of our new owners guide collection, which you may find very helpful as it addresses with practical tips and information all the areas where new owners have the most questions about. Our recommendations comply with
minimal welfare advice, but give options to surpass it whenever individually possible.
Getting Started - New Owners' Most Helpful Guides
Since we have got members and enquiries from all over the world, we find it very helpful if you please added your country, state/province or UK county or city to your details so we can always tailor any advice to what is relevant and available where you are straight away. Click on your username on the top bar, then go to account details and then down to location. This makes it appear with every post you make and saves everybody time. Thank you!