Welcome to the wonderful, life long joy of gardening, however, I would suggest getting a basic beginners' gardening book from the library You need to get some basic concepts and techniques in your mind before planting anything. In fact the questions you have asked would cover several books. Your questions are too wide ranging and complex for people to write full answers here.

Before you start thinking about sowing seeds have you prepared the area where you want to plant? Is it weed free and well cultivated? As for seeds, it is getting rather late in the year to sow most things, so you might be better off just dipping your toe in by trying a few plants in containers first. Seeds are very cheap and likely more reliable than getting a random bunch of freebies which might or might not suit your conditions. Be patient and start learning. Have fun.

contact your local COUNTY extension office.. and ask them for local references ...

its a bit late to start seeds this year.. you start them in spring.. when its cool.. not in july/august.. when seeds cant grow roots fast enough to overcome the heat of PA...

building a garden bed.. for fall planting is brilliant...

visit all local garden you can.. and just observe.. and if you are lucky ... find gardeners to talk with.. maybe you can even find a local garden club.. and be the youngest peep in the group... volunteer your labor and offer to be paid in plants.. and knowledge....

ken

Thank you, guys, so much for the advice. I have ensured that the weeds are out of the area I am working on. There is all new fresh soil placed down too. It's a nice little 10 by 10 in my backyard. I bought these plastic capsule things to put the seeds in to grow indoors before I placed them outside too.

I should have talked to the workers at home depot when I was there, but I was a little nervous to admit I was a first-timer, so that's why I found some online groups to try chatting with.

Next time I visit one of my local stores, I will talk to someone and try finding some books to read. I didn't even think of that. So thank you so much. I appreciate your help.

Home Depot is not the place to get gardening advice. I would do as Ken and Rhizo suggest and try to get local information from reputable sources and, above all, get yourself some beginners books. It is not necessary to buy in soil to make a garden unless the natural soil in your yard is very poor. And seeds do not necessarily need to be started indoors. It just depends on what you are growing and where you live. Many can be sown straight into the ground outsied. Before spending any more money, I really would recommend doing the research.

What do you want to grow? 10 x 10 is not very much space, so it's best to decide on what you really want to try and, of course, what is suitable for your location and climate.

I wanted to grow some flowers. I was thinking about some milkweeds and maybe some Petunias. I like Petunias. I was reading that mikweeds help with butterflies and bees so I thought maybe that would be a good idea

Perennials you probably want to start with purchased plants. The same is true for petunias, since it will take a long time for seeds to grow to be ready to flower. Some native plants can be very hard to start from seed, taking cycles of winter and summer. Read up on what you want to plant. Your library will have a bunch of books.

Visit botanical gardens and see what flourishes in your neighbors' gardens. If you're near Longwood, chat with them.

Some popular flowers include sunflowers, marigolds, zinnias, and petunias usually grow well in Pennsylvania. As for vegetables, consider growing tomatoes, peppers, lettuce, beans, carrots, and cucumbers.

- Indoors: Make sure they get enough light. If natural light is limited, consider using grow lights. Keep them properly watered, avoid over-watering, and use well-drained soil. Provide proper fertilization according to the needs of the plants.

- Outdoors: To promote plant growth outdoors, consider the following strategies:

- Soil preparation: Amend soil with organic matter to improve fertility and drainage.

- Mulch: Spread a layer of organic mulch around plants to retain moisture, suppress weeds, and regulate soil temperature.

- Watering: Water deeply and infrequently to promote deep root growth. Avoid overhead watering as this increases the risk of disease.

- Fertilize: Apply organic or slow-release fertilizer according to the specific requirements of the plants you are growing.

- Proper spacing: Ensure adequate spacing between plants to prevent overcrowding and promote air circulation.

- Regular maintenance: Prune or remove dead or diseased parts of plants in a timely manner. Monitor for pests and diseases and treat them early.

You can also read the article for more information. https://www.quictents.com/blogs/news/six-practical-ideas-for-your-gaining-an-affordable-and-creative-garden

Take a walk in your neighborhood! See what you like! Talk to the neighbors who are outside working in their gardens! Ask them questions! Ask the gardeners who are tending others' gardens. Take pictures of plants that seem to thrive in your neighborhood. Visit a local nursery. Ask questions there! Go to garden club workshops. Visit your local Master gardener websites! There are a lot of rabbit holes to go down with gardening! Have fun!