Newbie advice: Not looking for gains, just don't want massive losses

I hope I don't get flack for this, but I'm not only a crypto newbie but a total trading Luddite. I got a coinbase account, no wallet, for the purpose of being able to purchase from sites that offer discounts for buying with crypto. I have no real interest in buying crypto to make a profit or really looking to trade, I did all my pre-purchase checks and read the stuff coinbase asks you to as well as some of my own research so I know that getting fully into crypto isn't really for me.

One thing I'm not sure of though is knowing what to buy that has moderate fluctuation in value so as to not log in to make a purchase and find that £100 or so in coins I have in my account has suddenly dipped to being worth nothing (yes, I know losing everything is a risk in any investment)

I have (very small) amounts of USDC, Bitcoin Cash, and Cosmos, to use/trade into other coins or make purchases with.

I saw that Bitcoin has had some dips in market value, but this is `normal` for before a halving (still learning what that is)

Would the advice for a newb like me to not bother keeping anything in my account and just purchase coins when I want to use crypto to buy items, or could investing a small (like, £100 or so) amount into Bitcoin right now be a safe way to maybe bump up my future spending money?

I've been on this hell planet, and used the internet, long enough to know that nothing is a sure bet. But I just want to have the facts and tools behind me to feel comfortable holding small amounts without taking on bigger risks. Any (simple!) advice would be welcome :)