Depending on your reports, there might not be any need to really do some frontend coding. If the reports are good as they are and you just need to display them on SP, it's fairly simple with Excel Web Access web part.
I assume you want to automate processes as much as possible?
Consider the following: In your Excel report you have a named area which shows the wanted information already. This could be done with e.g. Pivot tables. As reports are created, the plain data gets automatically updated to Pivot tables. In SharePoint you can use Excel Web Access wp to show the named area on your page.
report/dashboard that shows the team members availability
This really depends where you need to pull the data from. If it's from Outlook, Calendar is a good choice (consider also Gantt-view). If it's from Skype for Business, you can achieve the current availability with a plain list showing the user's presence. If it's from (manually?) created Excel, the above mentioned report displaying works for this as well.