I find that experience gardeners assume we already know the basics, such as how much to water and when to fertilize.  Videos show us how to plant the seeds, but they don't show us how to care for them once planted.  They just say 'water'.  I'm a beginner gardener and have made some mistakes along the way.  With the help of my fellow experience garden club members, plus trial and error, I am getting there.  I would like to share my findings with you.  I hope this helps.

I have just started this section, so I will try to update a couple times a month.  For now, I will talk about vegetables.  As I learn more, I will provide updates on each section.

Carrots, Lettuce and Corn - Can they be planted together?  I read that root vegetables grow well with non root vegetables, like carrots and lettuce.  Since it was time to plant corn last month in the garden, I planted corn between the rows of carrots and found that doesn't work.  I heard that seeds need a lot of water to get them started especially carrots, so I watered twice daily (wasn't raining much in beginning of May), morning and night to make sure that the soil was very wet all the time.  My carrots started coming up but not corn!  I also have lettuce and it is doing great.  I dug up a couple of corn seeds and they didn't even spout.  What gives!

Carrots and lettuce need a lot of water to get the seeds to grow, but corn likes it dryer and warm soil.  
When planting different seeds/plants, need to find out the requirements needed for each.  Plant based on water needs, sun and soil type.

After I wrote the above, I went out to my garden and found that the corn finally sprouted!  They grew an inch overnight!  I feel that the warmer weather was a key factor for the corn in my case.  Cannot plant corn outside too early.  Here is a photo taken on June 8th.  The lettuce (planted much earlier) and corn are growing great but the carrots are growing painfully slow.  The soil is dryer so I'll try to water a little more to find the balance.  I haven't fertilized yet, so I'll try that as well.

Lettuce and Spinach - Nothing like fresh lettuce and spinach from the garden.  So why not grow it?  Well, easier said than done.  I planted both lettuce and spinach seeds in the garden but nothing came up.  Another garden club member showed me her lettuce, 5 inches tall and it was beginning of May.  What is her secret?  She bought seedlings from the nursery.  She said lettuce is very hard to grow from seed.

Okay, I love a challenge.  I planted more seeds but in pots, indoors under my grow lights in a warm room end of April and this time they grew. 
 Once the weather got warmer and plants taller, I transplanted into the garden.  Now they are tall.  Every morning I go out and nibble as I check their progress.  I try to eat the lower leaves so that they do not sit in the dirt.  So far the slugs have not found them :-)

Lettuce likes cool weather and constantly wet/moist soil or they will taste bitter.  I planted more lettuce and spinach seeds indoors but most of them didn't come up or grew so slow.  The seeds don't like to be moved, so need to mist them instead of using a watering can.  Indoors under the grow lights can get too warm for lettuce, so I moved them to the window sill for natural light.  They are starting to do better.

Update July 19
Here is an update as of July 19th of what it looks like now.  Lettuce is now bolting due to the heat so it won't last much longer.  I was getting a good hand full of lettuce every day from the 5 plants.  Spinach was okay.  It bolted before I got many leaves off them.  Gotta water more and give them some shade.
Corn is doing very well too.  Can't see the lettuce anymore.
Carrots not doing very well at all.  I only got one that looks promising, so I got to work on that.  I'll try again in a couple of weeks, so stay tuned.

Want something easy to grow?  Try something in the squash category.  I grow them from seeds, and they grow so well that a package of seeds can produce a lot.  So share them with a friend and keep some for future years.  I had seeds that are over 5 years and they still grew.  
This year I have a zucchini, Early Yellow Straightneck Squash and Scallopini aka Pattypans (Sunburst).  All are growing very well and are sure morale booster.   I have never grown or eaten Scallopini and the Straightneck Squash, so looking forward to see what they taste like.  They are from my niece.  Apparently both tastes like a zucchini so can't go wrong.  These plants can take up a lot of room, but this year they grew to the perfect size.  Just 2 ft by 2 ft.  Take up much less than pumpkins.
Here are photos from July 25, 2020.
Two plants here     Scallopini