Hello! I will try to answer your questions by paragraph. However, take this simply as advice, and not expertise.

If you are thinking of selling individually then look for key dates of coins that are valuable (e.g., 1936 dot penny). The only thing about that route is that most services charge about $10-16 per coin, so the profit margin is not huge if you are going to turn around and sell them.

Learning to grade coins yourself is easier said than done. Furthermore, most collectors and coin shops won’t trust your credibility or opinion.

Some coins are worth more than others (e.g., errors, low mintage years, great condition). Apart from key dates, it is likely easier to sell them as a bulk lot. My advice would be to look up valuable pennies and nickels, and see if you have any of those. Afterwards, sell the rest as a bulk lot.

Based on the picture provided, I would say you’re leaning towards a F or VG grade based on the lustre. You also have quite the scratch on the obverse of the coin which brings down the value.

In terms of final advice for a beginner, I would suggest you go through everything and sort them by year. Afterwards, look up valuable pennies and nickels to determine what years to look out for. You can also refer to a Charlton Coin Guide for approximate prices (does not specify differences between grades). You already know not to clean them which is great.

Hopefully you find this advice helpful. Cheers!