Wonder if anyone would know what I can do (information in text)??

I'd decorate and then varnish as the varnish will then protect whatever you put on them. The varnish I guess depends on the kind of finish you want, matte, gloss etc I'm guessing standard varnish would do the job

You might have to kiln the wood first depending on the wood and size to prevent rotting

@Jasmine ooo thank you that's helpful! Would you use like acrylic varnish or beeswax? They're the two that have come up 🤔

@Zara not to sound dumb but what does kiln the wood mean? 🤦🏼‍♀️

If the wood is fresh, it has moisture in it and needs to be dried to avoid it warping, shrinking, or splitting or getting fungus or rot on them. One way to do this is having them dry in a "kiln", which conditions it in a controlled environment. Clay is also kiln dried to make it hard. There are ways to air dry wood without a kiln if there isn't one near you - just check YouTube. It usually takes a long time but for small coaster sized pieces, should be okay.

@Zara thank you that's so helpful!

I’ve read if you coat the open face with wax it stops it cracking as well. So if it’s not very wide limbs then you could leave it uncut to dry out