Can someone please give advice on oak varnish

I have an existing oak table which has the top lacquered in a bright golden colour.

I am unsure if this is just a clear coat. I can post pictures on here if I can work out how

I have made a small table out of oak to sit near it and need to coat the top, and would like it to roughly match. I am an amateur at staining/varnishing and there are so many to pick from that I am getting lost in a sea of products at bunnings.

I tried to use an oil based stain on a pine entertainment unit once which turned into a disaster with it drying too quickly and i have been too scared to try ever since

Any advice on a nice easy to use finish for an oak top?

Also do i use a brush or a roller or what to apply?

Thanks guys!