I would take this to the Boglehead forum. They have a specific format for you write out your current holdings. The process of putting it together is important as you should understand it all. They can give more specific support.

Stop looking. Just stop.

Can you buy any funds on the market or are you limited to certain funds? Lots of funds in 401ks are dog shit - high fees and poor performance compared to other funds in the same class. If you’re limited in what you can buy, you need to look closely at costs, fees and performance of what’s available to make a good decision.

Right now the S&P is getting near the swing Low. The low should be around 4000-4200. Today it is 4224. So you are buying "Low".

If it gets down to 3500, that means it is because of new war involving many U.S ground troops. Unlikely, but could happen.

You can’t take a short term view with retirement funds. Stop watching it closely.

Just put in money every two weeks. Maybe 65-70% into an equity index fund. And forget it. You gave plenty of other things to focus on.

(once a year, rebalance mix in your portfolio. Done)

S and P 500 ETF at your age, stock funds.Don't complicate life. 'Months ahead'? It may take years for us to come out of this slight slump. You are getting the stock at cheap right now. It's not about if your balance goes up monthly, it's about you collecting shares of Voo for example. Look at the number of shares, not their price. Once they go up, the more shares you have, the more money you make. Collect the shares regardless of the price. Keep the fees low.

Market goes up and down but trends up over the life time. Relax and keep investing

I am down 8% and started job 5 months back. I have been working for 20 years so have 401k at another employer but starting here new so need to allocate in different funds. Help me reinvest my 401k -what type of funds? 100% balanced or 25/25/25/25 different funds so I have growth potential available in months ahead. I am 45. Thx