I hold some coins but I wonder if I am making profit that way.
Take a look at some historical values of Bitcoin. Check out what the coin was worth 1 year ago, 3, 5, or 10 years ago. Then imagine what that USD value would be today if you just bought it back than and did nothing else besides keeping it in your wallet. You can use
What if I hodl for historical prices for example.
Trading really require more skills and knowledge of crypto and the trading platform, hence I don't want to rush in.
Good choice. Trading is a profitable way of increasing your wealth, but only if you know what you are doing. Most people don't and they lose the little they had. I wrote a topic on that subject not that long ago. Check out
What Can Happen If You Want to Trade Cryptocurrencies, but You Don’t Know How? if you want.
So, are there ways to increase my bag without Trading?
What do you do for a living? If you have a job, can a part of your salary be in Bitcoin? If not, you can just leave a little amount from each paycheck and buy bitcoin with it. Do some freelance work and get paid in crypto. There are many possibilities, it depends on your skills and motivations.
Staking - It's quite safe to stake and grow your coins but slashing would result in loss of stake
A part of the stake, yes. But not the entire bag of course. I remember reading about Polkadot a few months ago and they have such a slashing feature. It's applied both to validators and delegators, so you need to be careful who you delegate your rights to if you are interested in that kind of thing. Avalanche, for example, has no slashing feature.