If you have premium, there are already some seating numbers in the free files. Otherwise, pick a design program to get familiar with. For this it won’t be complicated. Inkscape is free and fairly intuitive-I knew zero about it starting out. You ‘could’ make these directly in Glowforge as these are just rectangles with words on them.
Welcome to the forum, it’s normal to feel a bit overwhelmed on day one of owning your but you will soon pick it up as you want to make items and it won’t take you many pieces to learn everything you need to know to make anything you want.
The large seating chart in the first picture looks like it is using some kind of embossing trick for the gold text. You could do something similar by using the GF to cut some kind of gold decal material. However, finding the right stuff and then applying it to the poster paper would be tricky. I would not look to the laser first for that kind of sign.
For the table signs you can make the text out of acrylic but it will be easiest if your design is such that it can be cut out in one piece… Like, no loose dots on is. Same goes for raised letters on the book cover. You can do loose pieces, it is just more advanced work and you are just getting started.
Welcome to to the community. My best advice would be to first learn a design program. There are several to choose from. Just find the one that feels best to you. Have you gone through all the steps to begin using your machine? As a ‘veteran’ user now of 5 years, I knew nothing about lasers nor how to design for one. While I was waiting for my Glowforge, I began the learning curve to design. It’s not quite an instant gratification thing, but is sure worth the time and effort spent.