Hey guys,
I'm fairly new to bonsai and I managed to get some new material but I have no idea where to start. Any advice is appreciated

I would style the trunk on the bigger one now and leave to grow a couple of years. The only cut I would do now is by the first branch to the right. There are two branches growing from the same location on the trunk. One of Them has to go sooner or later. I would do it now. Which one to cut depends on which style you are looking for, how you bend the trunk and your personal taste.

The other ones I would dig into the ground and wait a few years before any styling.

Br
Magnus

Forget about styling these trees. They seem barely alive. First get them healthy.
You're not keeping them indoors I hope ? They shouldn't be in bonsai pots either.

No no I'm not keeping them indoors. They are just a bit battered due to travel.

How long have these been in these pots? If you bought them like this, I would return them. I do not think all of these will live based on what I can see. I hope I am wrong but..

Anything that you would call bonsai would have a pretty thick trunk, which none of these have. I would put these outdoors in the biggest container possible and let them grow until they have a thick enough trunk. Maybe the biggest possible container is your yard, and that would be great. Look at them every now and then and ask yourself how thick he trunk should be, where the branches should go, how does this tree compare with the trees you were looking at online yesterday (hint, hint). They have a couple of years to go before they are ready for styling.