The teeth that are next to my two front teeth are small. What should I get to make them better? (Photo)

Braces, or Invisalign may very well be an option for you, but there is more to it than just the overlap.  How do they relate to the bottom teeth?  You should have a thorough evaluation by an orthodontist for direction.

For mild relapse cases, Invisalign Express 10 is a good option. This is an expedited Invisalign treatment that consists of 10 sets of trays. In order to evaluate the best treatment options for you, it is recommended that you have a comprehensive evaluation with an Orthodontist. 

Over time, teeth tend to drift forward, giving the appearance of "crowding" or "overlapping". Orthodontic treatment followed by proper retention can likely help to improve the positioning of your teeth.  

Often times after ideal alignment of front teeth ( even the roots that you can't see) the teeth are in a very healthy position BUT the edges of the teeth AND the shape of the teeth are still distracting ( don't look 'straight').  By simple contouring artistically the edges and shapes a...

Absolutely you could but it is a very bad idea.  You already have decay and poor hygiene.  You may find you destroy your mouth in the process.Go back to the dentist (obviously concerned about your best intrests) and discuss what you need to do to make your mouth healthy and how to...

Yes, that is possible with intentional root canal treatment and veneers. But it's not advisable. It's my advice to go for aligners, you will get results very fast without compromising your healthy tooth structure.