I have a LVL5 Warlock (https://www.dndbeyond.com/profile/Bruceohughes/characters/4855035) with Pact of the Tome and Book of Ancient Secrets. I chose Find Familiar as one of my starting Rituals. My familiar is a home-brewed Dung Beetle currently.

My question is; do familiars stats change as i level? Do they level up?

Thanks in advance!

In 5E there aren't any mechanics for familiars to get more powerful as you gain levels.

You can, however, protect your familiar with spells, and those will tend to improve as you level up.

Also when you channel a spell through your familiar, it uses your stats

Really?!? Would my familiar use my perception if i was looking thru its eyes?

I’d rule both you and it (it doesn’t say the familiar cant see) would use your own perception. But, say you’re looking through an Owl’s. It has advantage on Perception checks, so you would too. It’s funny like that.