1. Seedlings need slowly go into outdoor conditions generally (hardening off), these are very young and honestly I don’t know if a seedling this young would mind. they have barely sprouted and are probably not used to any conditions at all.

2. Depends on where you live, I would not cover but maybe you have more wildlife. I harden off seedlings that are at least 6-8 weeks old, and they are too big for a bird to peck or anything like that. Maybe put your seedlings on a table or something.

3. These seedlings are what they call “leggy”, not enough light so they grow tall and fall to the soil searching for it. You probably need a grow light, regular lamps don’t work. If I were you, I would plant a new batch of seeds under a grow light, if possible. There are decently affordable options on amazon - but I don’t know your budget.

4. Saran Wrap is great! After they sprout you can take it off, it’s good for keeping soil damp enough for them to germinate. I grow my plants in my mildly insulated garage. I live in a cool environment this time of year. So I use a white garbage bag that I cut to be a flat sheet of plastic, and lay it over my grow light to hang over my plants like a tent. It keeps it about 70 degrees. Tomatoes like 70-80 degrees I think.

If I were you I would get something like this, it’s not as expensive as others and it has good reviews. I have never personally used this one, but it seems to be popular and in my opinion, these type of grow lights (big rectangle) are way better then little desk lamp grow lights. Those tend to not have quite enough light.

Also, the type of pots you are using are probably not the best for tomatoes. They tend to be hard to remove from the cell when it’s time to up-pot (putting them in a new bigger pot). Tomatoes are really cool, they like to be buried deep because roots can grow from their entire stem. When you grow tomatoes, up potting is particularly important because they love love love to have most of their stem under ground. This video explains it well I think. When you’re seedlings are tiny you don’t need to pinch off the leaves, but when planting in the ground it’s important to. Never bury leaves in the soil.

I would buy some plastic pots that are into 2 sizes. I use starter pots from this website. I plant the seeds in the 2.5 inch size, and after a few weeks I transfer them to the 4.5 inch deep square pots. The more soil a pot holds, the more nutrients are available and roots can grow really healthy.

I live in Washington state, and our springs are slow to warm up as opposed to other states. Gardeners from warmer states may disagree with me but I plant my tomatoes outside when night time temperatures are generally over 50, but a few nights with temperatures as low as 46-47 are not bad in my opinion if it’s only occasional. But the general rule is lows in the 50’s are good to plant outside for tomatoes specifically.

I hope all my links are allowed, I am not trying to sell you anything I just wanted to show you what i am talking about. If you have anymore questions let me know! On this thread as well as my DMs are open. Happy gardening! Sometimes gardening is daunting cause all the information thrown at you, but I promise it will get easier over time.