My thoughts are as follows.
If you'd like to purchase real estate, it might make sense to reduce your 401k contribution to save for your first purchase. I agree with Steve that you would want to make sure not to reduce below 4% to lock in the match. I would never recommend not contributing the minimum to get the match.
I wouldn't take out your 401k funding to invest in real estate (even if you can). I believe with the CARES ACT, you'd need to show that COVID-19 affected you to be able to take out funding. Plus, you'd unplug your investments and would be taxed on any 401k funds that you take out. It also depends on your employer's rules.
A roth/roth 401k might be a good option for you. If your employer has a roth 401k option with good choices, you could use this if interested in contributing after tax. You'd be in a low tax bracket and would be paying taxes on a lower rate with tax-free growth (important with how young you are).
A Lowe's/Home Depot card's interest rate doesn't matter as long as you pay it off in full each month. The key to credit cards is making sure you pay it off in full each month.
Yes, opening up multiple lines in one month or having multiple hard inquiries in short succession will result in a drop to your credit score. It will likely return to normal in 3-6 months assuming you don't have any negative marks.