New to tomato and cucamelon

Hi all, I bought some golden sun tomatoes and cucamelon seeds and planted them on Friday 7th July. I think this was probably a bit late but I thought I would see what happens. Each packet said to cover them, which I did and shoots should be seen after 14-21 days so I left them to it. On checking them today they have sprouted quite fast so they were a bit restricted in the space they had. I'm just not sure what to do now. The packet says to transfer to 7.5cm pots when large enough then stand outside but how big should I let them get before I put them in a larger pot?
Any help appreciated as I have never tried to grow anything like this before, I also planted some chilli pepper seeds but they can only just slightly be seen at the top on the compost so are a bit slower than the other two.
(I am aware of the issues with adding photos so I may try to add photos tomorrow)
Thank you
Posts
Hi I'm in the midlands, I guess I was just impatient. Thank you for the advice, I will try again at the correct time next year. Do you think there is any point letting these continue to grow ?
Tomato...
Chilli...
Cucamelon...
Thanks
Thanks I will keep the chillies inside and hope for the best!
I was advised, by somebody who told me they grow seeds all the time, that seeds needed to be kept covered and in the dark so I put a book over the propagator that was kept in the house
as I hadn't grown seeds before but I now know that was very much incorrect and they needed light (quite embarrassed) but at least i may now get it correct next time!